mcm protocol manual

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MCMProLinx GatewayModbus Master/Slave

May 7, 2012

PROTOCOL MANUAL


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Your Feedback Please

We always want you to feel that you made the right decision to use our products. If you have suggestions, comments,compliments or complaints about our products, documentation, or support, please write or call us.

How to Contact Us

ProSoft Technology5201 Truxtun Ave., 3rd FloorBakersfield, CA 93309+1 (661) 716-5100+1 (661) 716-5101 (Fax)[email protected]

Copyright 2012 ProSoft Technology, Inc., all rights reserved.

MCM Protocol Manual

May 7 , 2012

ProSoft Technology , ProLinx , inRAx , ProTalk , and RadioLinx are Registered Trademarks of ProSoftTechnology, Inc. All other brand or product names are or may be trademarks of, and are used to identify productsand services of, their respective owners.

ProSoft TechnologyProduct Documentation

In an effort to conserve paper, ProSoft Technology no longer includes printed manuals with our product shipments.User Manuals, Datasheets, Sample Ladder Files, and Configuration Files are provided on the enclosed CD-ROM inAdobeAcrobat Reader file format (.PDFs). These product documentation files may also be freely downloaded fromour web site: www.prosoft-technology.com


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Important Installation Instructions

Power, Input, and Output (I/O) wiring must be in accordance with Class I, Division 2 wiring methods, Article 501-4 (b)of the National Electrical Code, NFPA 70 for installation in the U.S., or as specified in Section 18-1J2 of the CanadianElectrical Code for installations in Canada, and in accordance with the authority having jurisdiction. The followingwarnings must be heeded:

WARNING - EXPLOSION HAZARD - SUBSTITUTION OF COMPONENTS MAY IMPAIRSUITABILITY FOR CLASS I, DIV. 2;WARNING - EXPLOSION HAZARD - WHEN IN HAZARDOUS LOCATIONS, TURN OFFPOWER BEFORE REPLACING OR WIRING MODULESWARNING - EXPLOSION HAZARD - DO NOT DISCONNECT EQUIPMENT UNLESS POWERHAS BEEN SWITCHED OFF OR THE AREA IS KNOWN TO BE NON-HAZARDOUS.THIS DEVICE SHALL BE POWERED BY CLASS 2 OUTPUTS ONLY.

ProLinxProducts Warnings

WARNING EXPLOSION HAZARD DO NOT DISCONNECT EQUIPMENT UNLESSPOWER HAS BEEN SWITCHED OFF OR THE AREA IS KNOWN TO BE NON-HAZARDOUS.AVERTISSEMENT RISQUE D'EXPLOSION AVANT DE DCONNECTER L'EQUIPMENT,COUPER LE COURANT OU S'ASSURER QUE L'EMPLACEMENT EST DSIGN NONDANGEREUX.

ProLinx Gateways with Ethernet Ports

Series C ProLinx Gateways with Ethernet ports do NOT include the HTML Web Server. The HTML Web Servermust be ordered as an option. This option requires a factory-installed hardware addition. The HTML Web Server now

supports: 8 MB file storage for HTML files and associated graphics files (previously limited to 384K) 32K maximum HTML page size (previously limited to 16K)

To upgrade a previously purchased Series C model

Contact your ProSoft Technology distributor to order the upgrade and obtain a Returned Merchandise Authorization(RMA) to return the unit to ProSoft Technology.

To order a ProLinx Plus gateway with the -WEB option

Add -WEB to the standard ProLinx part number. For example, 5201-MNET-MCM-WEB.


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Markings

Label Markings

E183151

Class I Div 2

Groups A,B,C,D T6

-30C


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MCM ProLinx Gateway ContentsModbus Master/Slave Protocol Manual

ProSoft Technology, Inc. Page 5 of 92May 7, 2012

Contents

Your Feedback Please ........................................................................................................................ 2How to Contact Us .............................................................................................................................. 2ProSoft TechnologyProduct Documentation .................................................................................... 2Important Installation Instructions ....................................................................................................... 3ProLinxProducts Warnings ............................................................................................................... 3ProLinx Gateways with Ethernet Ports ............................................................................................... 3

To upgrade a previously purchased Series C model ..................................................................... 3To order a ProLinx Plus gateway with the -WEB option ................................................................ 3

Markings .............................................................................................................................................. 41 Start Here 9

1.1 System Requirements ............................................................................................. 101.2 Package Contents ................................................................................................... 111.3 Mounting the Gateway on a DIN-rail ....................................................................... 121.4 Connecting Power to the Unit ................................................................................. 131.5 Installing ProSoft Configuration Builder Software ................................................... 141.6 Using the Online Help ............................................................................................. 15

2 Functional Overview 172.1 Modbus Master/Slave Port(s) .................................................................................. 182.2 Serial Port Specifications ........................................................................................ 192.3 Modbus Master/Slave Port Specifications ............................................................... 202.4 Module Internal Database ....................................................................................... 21

2.4.1 Modbus Port Access to Database ........................................................................... 223 MCM Protocol Configuration 23

3.1 [Modbus Port x] ....................................................................................................... 253.1.1 Enabled ................................................................................................................... 253.1.2 RS Interface ............................................................................................................ 253.1.3 Type ......................................................................................................................... 253.1.4 Float Flag ................................................................................................................ 253.1.5 Float Start ................................................................................................................ 263.1.6 Float Offset .............................................................................................................. 263.1.7 Protocol ................................................................................................................... 263.1.8 Baud Rate ............................................................................................................... 273.1.9 Parity ....................................................................................................................... 273.1.10 Data Bits .................................................................................................................. 273.1.11 Stop Bits .................................................................................................................. 273.1.12 RTS On.................................................................................................................... 283.1.13 RTS Off.................................................................................................................... 283.1.14 Minimum Response Delay ...................................................................................... 283.1.15 Use CTS Line .......................................................................................................... 283.1.16 Response Timeout .................................................................................................. 283.1.17 Retry Count ............................................................................................................. 283.1.18 Internal Slave ID ...................................................................................................... 293.1.19 Bit Input Offset ......................................................................................................... 29


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Contents MCM ProLinx GatewayProtocol Manual Modbus Master/Slave

Page 6 of 92 ProSoft Technology, Inc.May 7, 2012

3.1.20 Word Input Offset .................................................................................................... 293.1.21 Output Offset........................................................................................................... 293.1.22 Holding Register Offset ........................................................................................... 303.1.23 Use Guard Band Timer ........................................................................................... 313.1.24 Guard Band Timeout .............................................................................................. 323.1.25 Minimum Command Delay ..................................................................................... 323.1.26 Error Delay Counter ................................................................................................ 333.1.27 Command Control Reg ........................................................................................... 33

3.2 [Modbus Port X Commands]................................................................................... 343.2.1 Enable ..................................................................................................................... 353.2.2 Internal Address ...................................................................................................... 353.2.3 Poll Interval ............................................................................................................. 353.2.4 Reg Count ............................................................................................................... 363.2.5 Swap Code ............................................................................................................. 363.2.6 Slave Address ......................................................................................................... 373.2.7 Modbus Function .................................................................................................... 373.2.8 MB Address in Device ............................................................................................ 38

4

Serial Port Modbus Error and Status Data 39

4.1 Viewing Error and Status Data ............................................................................... 404.2 Modbus Error and Status Data Area Addresses .................................................... 41

4.2.1 Modbus Ports: Error and Status ............................................................................. 414.2.2 Slave Port: General Port STATE and COMM STATE Status ................................. 424.2.3 Master Port: Command List Errors ......................................................................... 434.2.4 Master Port: Modbus Slave List Status .................................................................. 45

4.3 Error Codes ............................................................................................................. 474.3.1 Modbus Error Codes ............................................................................................... 47

5 Module Communication Error Codes 485.1.1 Command List Error Codes .................................................................................... 485.1.2 Modbus Configuration Error Word .......................................................................... 49

6 Communication Port Cables 516.1 Port 0, 1, 2, 3: RS-232 - Null Modem (DTE with Hardware Handshaking) ............ 526.2 Port 0, 1, 2, 3: RS-232 - Null Modem (DTE without Hardware Handshaking) ....... 536.3 Port 0, 1, 2, 3: RS-232 - DTE to DCE Modem Connection .................................... 546.4 Port 0, 1, 2, 3: RS-422 Interface Connections ........................................................ 556.5 Port 0, 1, 2, 3: RS-485 Interface Connections ........................................................ 56

7 LED Indicators 577.1

Base Module LEDs ................................................................................................. 58

7.2 LEDs for Serial Ports .............................................................................................. 59

8 Modbus Port Expander (4102/5102-MBS3-MBM) 618.1 [Modbus Master Port] ............................................................................................. 62

8.1.1 Internal Slave ID ..................................................................................................... 628.1.2 Protocol ................................................................................................................... 62


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MCM ProLinx Gateway ContentsModbus Master/Slave Protocol Manual


8.1.3 Baud Rate ............................................................................................................... 638.1.4 Parity ....................................................................................................................... 638.1.5 Data Bits .................................................................................................................. 638.1.6 Stop Bits .................................................................................................................. 648.1.7 RTS On.................................................................................................................... 648.1.8 RTS Off.................................................................................................................... 648.1.9 Minimum Response Delay ...................................................................................... 648.1.10 Use CTS Line .......................................................................................................... 648.1.11 Response Timeout .................................................................................................. 648.1.12 Retry Count ............................................................................................................. 65

8.2 [Modbus Slave Port x] ............................................................................................. 668.2.1 Enabled ................................................................................................................... 668.2.2 RS Interface ............................................................................................................ 668.2.3 Protocol ................................................................................................................... 668.2.4 Baud Rate ............................................................................................................... 678.2.5 Parity ....................................................................................................................... 688.2.6 Data Bits .................................................................................................................. 688.2.7 Stop Bits .................................................................................................................. 688.2.8 RTS On.................................................................................................................... 688.2.9 RTS Off.................................................................................................................... 688.2.10 Minimum Response Delay ...................................................................................... 688.2.11 Use CTS Line .......................................................................................................... 698.2.12 Use Guard Band Timer ........................................................................................... 698.2.13 Guard Band Timeout ............................................................................................... 708.2.14 Request Timeout ..................................................................................................... 708.2.15 Busy Timeout .......................................................................................................... 708.2.16 Busy Timeout .......................................................................................................... 71

9 Reference 739.1 Modbus Protocol Specification ................................................................................ 74

9.1.1 Read Coil Status (Function Code 01) ..................................................................... 749.1.2 Read Input Status (Function Code 02) .................................................................... 759.1.3 Read Holding Registers (Function Code 03) .......................................................... 769.1.4 Read Input Registers (Function Code 04) ............................................................... 779.1.5 Force Single Coil (Function Code 05) ..................................................................... 789.1.6 Preset Single Register (Function Code 06) ............................................................. 799.1.7 Diagnostics (Function Code 08) .............................................................................. 809.1.8 Force Multiple Coils (Function Code 15) ................................................................. 829.1.9 Preset Multiple Registers (Function Code 16) ........................................................ 839.1.10 Modbus Exception Responses ................................................................................ 84

9.2 Moving Data using the Data Map ............................................................................ 87 10 Support, Service & Warranty 89

Contacting Technical Support ........................................................................................................... 8910.1 Return Material Authorization (RMA) Policies and ConditionsError! Bookmark not defined.10.1.1 Returning Any Product ..............................................Error! Bookmark not defined.10.1.2 Returning Units Under Warranty ...............................Error! Bookmark not defined.10.1.3 Returning Units Out of Warranty ...............................Error! Bookmark not defined.

10.2 LIMITED WARRANTY ...............................................Error! Bookmark not defined.10.2.1 What Is Covered By This Warranty ...........................Error! Bookmark not defined.10.2.2 What Is Not Covered By This Warranty ....................Error! Bookmark not defined.


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Contents MCM ProLinx GatewayProtocol Manual Modbus Master/Slave


10.2.3 Disclaimer Regarding High Risk Activities ................Error! Bookmark not defined.10.2.4 Intellectual Property Indemnity .................................Error! Bookmark not defined.10.2.5 Disclaimer of all Other Warranties ............................ Error! Bookmark not defined.10.2.6 Limitation of Remedies ** ......................................... Error! Bookmark not defined.10.2.7 Time Limit for Bringing Suit ....................................... Error! Bookmark not defined.10.2.8 No Other Warranties ................................................. Error! Bookmark not defined.10.2.9 Allocation of Risks ....................................................Error! Bookmark not defined.10.2.10 Controlling Law and Severability ..............................Error! Bookmark not defined.

Index 91


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MCM ProLinx Gateway Start HereModbus Master/Slave Protocol Manual


1 Start Here

In This Chapter

System Requirements ........................................................................... 10

Package Contents ................................................................................. 11

Mounting the Gateway on a DIN-rail ..................................................... 12

Connecting Power to the Unit ................................................................ 13

Installing ProSoft Configuration Builder Software .......... ........... .......... ... 14

Using the Online Help ........................................................................... 15


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Start Here MCM ProLinx GatewayProtocol Manual Modbus Master/Slave


1.1 System Requirements

The configuration software for the MCM gateway requires the following minimumhardware and software components: Pentium II 450 MHz minimum. Pentium III 733 MHz (or better)

recommended 128 Mbytes of RAM minimum, 256 Mbytes of RAM recommended 100 Mbytes of free hard disk space (or more based on application

requirements) 256-color VGA graphics adapter, 800 x 600 minimum resolution (True Color

1024 768 recommended) CD-ROM driveSupported operating systems: Microsoft Windows 7(32 bit) (64bit not tested) Microsoft Windows Vista (not tested) Microsoft Windows XP Professional with Service Pack 1 or 2 Microsoft Windows 2000 Professional with Service Pack 1, 2, or 3 (not

tested) Microsoft Windows Server 2003 (not tested)


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1.2 Package Contents

The following components are included with your MCM gateway, and are allrequired for installation and configuration.

Important: Before beginning the installation, please verify that all of the followingitems are present.

Qty. Part Name Part Number Part Description

1 MCM gateway PLX-#### ProLinx communication gateway

1 Cable Cable #15, RS232Null Modem

For RS232 Connection from a PC to theCFG Port of the gateway

Varies Cable Cable #9, Mini-DIN8 to DB9 MaleAdapter

For DB9 Connection to gateways Port. OneDIN to DB-9M cable included perconfigurable serial port, plus one forgateway configuration

Varies Adapter 1454-9F Adapters, DB9 Female to Screw Terminal.For RS422 or RS485 Connections to eachserial application port of the gateway

1 ProSoft Solutions CD Contains sample programs, utilities anddocumentation for the MCM gateway.

If any of these components are missing, please contact ProSoft TechnologySupport for replacements.


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1.3 Mounting the Gateway on a DIN-rail

ProLinx 5000/6000 Series gateway


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1.4 Connecting Power to the Unit

WARNING: Ensure that you do not reverse polarity when applying power to thegateway. This will cause damage to the gateways power supply.


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1.5 Installing ProSoft Configuration Builder Software

You must install the ProSoft Configuration Builder (PCB) software to configurethe gateway. You can always get the newest version of ProSoft ConfigurationBuilderfrom the ProSoft Technology website.

To install ProSoft Configuration Builder from the ProSoft Technology website

1 Open your web browser and navigate to http://www.prosoft-technology.com/pcb

2 Click thelink at the Current Release Versionsection to download the latestversion of ProSoft Configuration Builder.

3 Choose SAVE or SAVE FILE when prompted.4 Save the file to your Windows Desktop, so that you can find it easily when

you have finished downloading.5 When the download is complete, locate and open the file, and then follow the

instructions on your screen to install the program.If you do not have access to the Internet, you can install ProSoft ConfigurationBuilderfrom the ProSoft Solutions Product CD-ROM, included in the packagewith your gateway.

To install ProSoft Configuration Builder from the Product CD-ROM

1 Insert the ProSoft Solutions Product CD-ROMinto the CD-ROM drive of yourPC. Wait for the startup screen to appear.

2 On the startup screen, click PRODUCT DOCUMENTATION. This action opens aWindows Explorerfile tree window.

3 Click to open the UTILITIES folder. This folder contains all of the applicationsand files you will need to set up and configure your gateway.

4 Double-click the SETUP CONFIGURATION TOOL folder, double-click the

PCB_*.EXE file and follow the instructions on your screen to install thesoftware on your PC. The information represented by the "*" character in thefile name is the PCBversion number and, therefore, subject to change asnew versions of PCBare released.

Note: Many of the configuration and maintenance procedures use files and otherutilities on the CD-ROM. You may wish to copy the files from the Utilitiesfolderon the CD-ROM to a convenient location on your hard drive.


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1.6 Using the Online Help

Most of the information needed to help you use is provided in a Help Systemthat is always available whenever you are running . The Help System does notrequire an Internet connection.

To view the help pages, start , open the HELP menu, and then choose CONTENTS.


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MCM ProLinx Gateway Functional OverviewModbus Master/Slave Protocol Manual


2 Functional Overview

In This Chapter

Modbus Master/Slave Port(s) ................................................................ 18

Serial Port Specifications....................................................................... 19

Modbus Master/Slave Port Specifications ............................................. 20

Module Internal Database ..................................................................... 21

The Modbus Master/Slave protocol driver may exist in a single port (MCM) or a

multiple port (MCM4) implementation. In either case, each port can beindependently configured as a Master or Slave port to interface, as required, withother Modbus devices.


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Functional Overview MCM ProLinx GatewayProtocol Manual Modbus Master/Slave


2.1 Modbus Master/Slave Port(s)

The Modbus Master ports can be used to continuously interface with Modbusslave devices over a serial communication interface (RS-232, RS-422 or RS-485). Each Master port may have up to 100 user defined commands whichdetermine the Modbus read/write messages issued to each slave attached to theport.In addition, the gateway can be configured to poll slave devices that are notresponding to commands at a lower priority (slow-poll mode). If a slave devicehas failed to respond to a command after a user-defined number of retries, thedriver will recognize the slave is experiencing a communication failure. In thiscase, if you have set a non-zero value in the Error Delay Count parameter in theMaster port configuration, then, as the driver comes to a command on the MasterCommand List that should be sent to the failing slave, instead of sending thecommand, the driver will skip the command and decrement the error delaycounter value by one.When the number of commands have been skipped is equal to the value set in

the Error Delay Count parameter, the error delay counter will have beendecremented go zero and the driver will send next command for that node in thecommand list. If the slave responds properly to this command, the driver willresume normal polling of this slave. If the new command fails, the driver willcontinue to recognize the slave is experiencing communication problems andrepeat the process of skipping commands and decrementing the error delaycounter before trying to send another command to that slave. This has the effectof putting the slave in a low-priority, slow-poll mode until it begins tocommunicate normally again.


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2.2 Serial Port Specifications

Type Specifications

Serial Ports

Serial Port Adapter Cables One Mini DIN to DB-9M adapter cable included foreach configurable serial port

Config Port Connector/ Pinout DB-9F connector / DTE pinout

Serial Port Isolation 2500V RMS port-to-port isolation per UL 1577.3000V DC min. port to ground and port to logicpower isolation.

Serial Port Protection RS-485/422 port interface lines TVS diode protectedat +/- 27V standoff voltage.RS-232 port interface lines fault protected to +/- 36V

power on, +/- 40V power off.Note: On all ProLinx gateways, data from the application port on the main board,serial Port 0, is not buffered. Packets go directly to and from the serial chipset tothe processor. This has the potential to cause the serial communications tobecome erratic at baud rates above 38,400 baud.ProLinx gateways with 4 serial ports have a separate serial interface board forserial Ports 1, 2, and 3. These serial ports are buffered and can handlecommunications up to 115,200 baud.


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2.3 Modbus Master/Slave Port Specifications

Type Specifications

General Parameters

Internal Database Up to 4000 registers (words) available.

Communication parameters Port 0: Baud Rate: 110 to 115K baud possible110 to 38.4K baud recommended for all applications.Higher baud rates are recommended only for usewith very slow Modbus polling rates (e.g. 1commandor less per second)Port 1, 2, 3: Baud Rate: 110 to 115K baudStop Bits: 1 or 2Data Size: 5 to 8 bitsParity: None, Even, Odd, Mark, SpaceRTS Timing delays: 0 to 65535 milliseconds

Modbus Modes RTU mode (binary) with CRC-16ASCII mode with LRC error checking

Floating Point Data Floating point data movement supported, includingconfigurable support for Enron implementation

Modbus Function Codes 1: Read Coil Status2: Read Input Status3: Read Holding Registers4: Read Input Registers5: Force (Write) Single Coil6: Preset (Write) Single Register15: Force(Write) Multiple Coils16: Force (Write) Multiple Register

Modbus Master

Command List Up to 100 command per Master port, each fullyconfigurable for function, slave address, registerto/from addressing and word/bit count

Status Data Error codes available on an individual commandbasis. In addition, a slave status list is maintainedper active Modbus Master port.

Polling of command list Configurable polling of command list, includingcontinuous and on change of data

Modbus Slave

Node address 1 to 247 (software selectable)

Status Data Error codes, counters and port status available perconfigured slave port starting at memory register4400.


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2.4 Module Internal Database

The internal gateway database is central to the functionality of the gateway. Thisdatabase is shared between all the ports on the gateway This permits data fromdevices on one communication network port to be viewed and controlled bydevices on another port or network.

Other ProLinxProtocolDriver

ModbusSlaveDriver

ModbusMasterDriver

ProLinxCommunication

GatewaysInternal

Database(Up to 4000 regs)

Other ProLinxProtocolDriver

ModbusSlaveDriver

ModbusMasterDriver

ProLinxCommunication

GatewaysInternal

Database

The Master driver uses the database in two ways: A read command issued to a slave device by the Master driver will return the

slave data into the internal database. A write command issued to a slave device by the Master driver uses the data

in the internal database as the source data to send to the slave.The slave driver allows external Master devices to access the database, readingdata from the database or writing data to the database. External Modbus Masterdevices can monitor and control data in this database through any port

configured as a slave.Status and error data from the slave and Master ports generated by the gatewaycan be mapped into the internal database, where it can be retrieved by eitherprotocol driver.


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2.4.1 Modbus Port Access to Database

The Modbus slave support in the gateway permits remote Master applications(that is, HMI software, Quantum processors, and so on) to read from and write tothe gateways database.

When configured as a slave, the internal database of the MCM gateway is usedas the source for read requests and the destination for write requests fromremote Masters. Access to the database is controlled by the command typereceived in the incoming message from the remote Master. The following tabledefines the relationship of the gateways internal database to the addressesrequired in the incoming Modbus TCP/IP requests:Database Address Modbus Address

0 40001 (five-digit addressing) or 400001 (six-digit addressing)

1000 41001 or 410001

2000 42001 or 420001

3000 43001 or 430001

3999 44000 or 440000The following virtual addresses are not part of the normal gateway user databaseand are not valid addresses for standard data. However, these addresses maybe used for incoming commands that are requesting 32-bit floating-point data. Touse addresses in this upper range requires you to:1 Set the Float Flag (page 25) to YES2 Set the Float Start (page 26) to a database address in the range below3 Set the Float Offset (page 26) to a database address in the gateway user

memory area shown above.Remember that, once you do this, all data in addresses above the Float Offsetaddress will be treated as 32-bit floating-point data and require two gatewaymemory registers per Modbus address.Database Address Modbus Address

4000 44001 (five-digit addressing) or 440001 (six-digit addressing)

5000 45001 or 450001

6000 46001or 460001

7000 47001 or 470001

8000 48001 or 480001

9000 49001or 490001

9999 50000 or 500000


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MCM ProLinx Gateway MCM Protocol ConfigurationModbus Master/Slave Protocol Manual


3 MCM Protocol Configuration

In This Chapter

[Modbus Port x] ..................................................................................... 25

[Modbus Port X Commands] ................................................................. 34


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MCM Protocol Configuration MCM ProLinx GatewayProtocol Manual Modbus Master/Slave


#This is an example of a Master port using Modbus RTU protocol

[Modbus Port 0]

# Settings required by both Master and Slave

Enabled : Yes #Port enable flag Y=Yes, N=NoRS Interface : 0 #0=RS-232, 1=RS-485, 2=RS-422Type : Master #Port type M=Master, S=Slave

Float Flag : No #Use floating data type Y=Yes, N=NoFloat Start : 7000 #Register offset in message for floatsFloat Offset : 2000 #Internal Address for floats

Protocol : RTU #Modbus Protocol R=RTU, A=ASCIIBaud Rate : 384 #Baud rate for portParity : None #N=None, O=Odd, E=EvenData Bits : 8 #5 to 8 data bits for messagesStop Bits : 1 #1 or 2 stop bits for messagesRTS On : 0 #Delay after RTS set before message sent (mSec)

RTS Off : 1 #Delay after message before RTS dropped(mSec)Minimum Response Delay : 2 #Number of mSec to delay before resposeUse CTS Line : No #Monitor CTS modem line (Y/N)Response Timeout : 1000 #mSec for response timeout of commandRetry Count : 2 #retry count for failed requests

# Settings required for Slave DriverInternal Slave ID : 1 #Modbus Node address for this port on networkBit Input Offset : 0 #Internal DB offset to bit input dataWord Input Offset : 0 #Internal DB offset to word input dataOutput Offset : 0 #Internal DB offset to bit output dataHolding Register Offset : 0 #Internal DB offset to holding reg dataUse Guard Band Timer : N #Use packet gap timeout for messagesGuard Band Timeout : 0 #0=Use default for baudrate, or set timeout

# Settings required for Master DriverMinimum Command Delay : 0 #mSec delay between commandsError Delay Counter : 100 #0-65535 Command cycle count if errorCommand Control Reg : -1 #DB start reg for Cmd Control (-1=disable)

[Modbus Port 0 Commands]# Internal Poll Reg Swap Node Modbus MB Address# Enable Address Interval Count Code Address Func in DeviceSTART

1 0 0 10 0 1 3 01 10 0 10 0 1 4 10

END


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3.1 [Modbus Port x]

The [Modbus Port x] sections of the CFG file, where x stands for 0, 1, 2, or 3, setthe Modbus Master and slave port communication parameters and define theprotocol-specific settings.

3.1.1 Enabled

YES or NOThis flag specifies if the port on the gateway will be utilized. If the parameter isset to NO, the port will not be used. If the parameter is set to YES, the port will beused.

3.1.2 RS Interface

0 = RS-2321 = RS-4852 = RS-422

This parameter is used when Ports 1, 2, and 3 are present to configure theelectrical interface for these ports.RS Interface selections for Port 0 are done with a jumper (electrical shunt) on theback of the gateway.

3.1.3 Type

MASTER or SLAVEThis parameter defines if the port will emulate a Master or slave device. Choosea value of MASTER to make the port function as a Modbus Master. Choose SLAVEto make the port function as a Modbus slave.

3.1.4 Float Flag

YES or NOThis flag specifies how the Slave driver will respond to Function Code 3, 6, and16 commands (read and write Holding Registers) from a remote Master when itis moving 32-bit floating-point data.If the remote Master expects to receive or will send one complete 32-bit floating-point value for each count of one (1), then set this parameter to YES. When set toYES, the Slave driver will return values from two consecutive 16-bit internalmemory registers (32 total bits) for each count in the read command, or receive32-bits per count from the Master for write commands. Example: Count = 10,

Slave driver will send 20 16-bit registers for 10 total 32-bit floating-point values.If, however, the remote Master sends a count of two (2) for each 32-bit floating-point value it expects to receive or send, or, if you do not plan to use floating-point data in your application, then set this parameter to NO, which is the defaultsetting.You will also need to set the Float Startand Float Offsetparameters toappropriate values whenever the Float Flagparameter is set to YES.


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3.1.5 Float Start

0 TO 65535Whenever the Float Flagparameter is set to YES, this parameter determines thelowest Modbus Address, received in commands from a remote Master, to

consider as requests to read or write floating-point data. All commands withaddress values greater than or equal to this value will be considered floating-point data requests. All commands with address values less than this value willbe considered normal 16-bit register data requests.This parameter is used only if the Float Flagis set to YES. For example, if a valueof 7000 is entered, all commands received with addresses of 47001 (or 407001)and above will be considered as requests for floating-point data and 32-bits ofdata will be returned for each count of one in the command.You will also need to set the Float Offsetparameter to an appropriate valuewhenever the Float Flagparameter is set to YES.

3.1.6 Float Offset

0 TO 3998This parameter defines the starting register for floating-point data in the internalgateway database. This parameter is used only if the Float Flagis set to YES.For example, if the Float Offsetvalue is set to 3000 and the Float Startparameteris set to 7000, the data returned as floating-point data for register 47001 (or407001) will actually come from internal gateway registers 3000 and 3001. If therequested address was 47002 (407002), the data will be returned from internalregisters 3002 and 3003. If the requested address was 47101 (407101), the datawill be returned from internal registers 3200 and 3201; and so on.

3.1.7 ProtocolRTUASCIIThis parameter specifies the Modbus protocol version to be used on the port.Valid Protocols are RTU and ASCII.


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3.1.8 Baud Rate

This is the baud rate to be used on the port. Enter the baud rate as a value.Baud Rate Parameter Value

110 110

150 150300 300

600 600

1200 12 OR 1200

2400 24 OR 2400

4800 48 OR 4800

9600 96 OR 9600

19,200 19,192 OR 19200

38,400 38,384 OR 38400

57,600 57 OR 576

115,200 115 OR 1152

Note: On all ProLinx gateways, data from the application port on the main board,serial Port 0, is not buffered. Packets go directly to and from the serial chipset tothe processor. This has the potential to cause the serial communications tobecome erratic at baud rates above 38,400 baud.ProLinx gateways with 4 serial ports have a separate serial interface board forserial Ports 1, 2, and 3. These serial ports are buffered, and can handlecommunications up to 115,200 baud.

3.1.9 Parity

None, Odd, Even

Parity is a simple error checking algorithm used in serial communication. Thisparameter specifies the type of parity checking to use.All devices communicating through this port must use the same parity setting.

3.1.10 Data Bits

7or 8This parameter sets the number of data bits for each word used by the protocol.All devices communicating through this port must use the same number of databits.

3.1.11 Stop Bits

1 or 2Stop bits signal the end of a character in the data stream. For most applications,use one stop bit. For slower devices that require more time to re-synchronize,use two stop bits.All devices communicating through this port must use the same number of stopbits.


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3.1.12 RTS On

0 to 65535millisecondsThis parameter sets the number of milliseconds to delay after Ready To Send(RTS) is asserted before data will be transmitted.

3.1.13 RTS Off

0 to 65535 millisecondsThis parameter sets the number of milliseconds to delay after the last byte ofdata is sent before the RTS modem signal will be set low.

3.1.14 Minimum Response Delay

0 to 65535This parameter is used only when the port is configured as a slave. It sets thenumber of milliseconds to wait before responding to a command received on the

port from a remote Master. This delay is sometimes required to accommodateslower Master devices.

3.1.15 Use CTS Line

YES or NOThis parameter specifies if the Clear To Send (CTS) modem control line is to beused or not. If the parameter is set to NO, the CTS line will not be monitored. Ifthe parameter is set to YES, the CTS line will be monitored and must be highbefore the gateway will send data. Normally, this parameter is required whenhalf-duplex modems are used for communication (2-wire). This procedure iscommonly referred to as hardware handshaking.

3.1.16 Response Timeout

0 TO 65535 millisecondsThis parameter sets the command response timeout period in 1 millisecondincrements. This is the time that a port configured as a Master will wait for aresponse from the addressed slave before re-transmitting the command (Retries)or skipping to the next command in the Command List. The value to set dependson the communication network used and the expected response time (plus a littleextra) of the slowest device on the network.

3.1.17 Retry Count

0 to 10This parameter specifies the number of times a command will be retried if it fails.


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3.1.18 Internal Slave ID

0 TO 255When the port is configured as a slave, this parameter defines the virtual Modbusslave address for the port. Any commands received on the slave port, addressed

to the node address entered here, will be processed by the gateway. Each slavedevice on the network must be assigned a unique address.

3.1.19 Bit Input Offset

0 TO 3999When the port is configured as a slave, this parameter specifies the internaldatabase address to use as the zero address or starting point for binary InputStatus data. Input Status data is read-only data, requested by Modbus FunctionCode 2 commands (Read Input Status). For example, if this parameter is set to150 and a Function Code 2 command is received requesting Input Statusaddress 0 (virtual Modbus Address 10001 or 100001), the data returned in the

response will be the bit value at register 150, bit 0 in the gateway's database.

3.1.20 Word Input Offset

0 TO 3999When the port is configured as a slave, this parameter specifies the internaldatabase address to use as the zero address or starting point for Input Register(16-bit integer) data. Input Register data is read-only data, requested by ModbusFunction Code 4 commands (Read Input Registers). For example, if thisparameter is set to 500 and a Function Code 4 command is received requestingInput Register address 0 (virtual Modbus address 30001 or 300001), the datareturned in the response will be the value at register 500 in the gateway's

database.

3.1.21 Output Offset

0 TO 3999When the port is configured as a slave, this parameter specifies the internaldatabase address to use as the zero address or starting point for binary outputCoil data. Coil data is read by Modbus Function Code 1 commands (Read Coils)and written by Function Codes 5 (Force Single Coil) or Function Code 15 (ForceMultiple Coils). For example, if this parameter is set to 50 and a Function Code 1command is received requesting Coil address 0 (virtual Modbus Coil address00001 or 000001), the data returned in the response will be the value at register

50, bit 0 in the gateway's database.


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3.1.22 Holding Register Offset

0 TO 3999When the port is configured as a slave, this parameter specifies the internaldatabase address to use as the zero address or starting point for Holding

Register (16-bit integer) data. Holding Register data is read by Modbus FunctionCode 3 commands (Read Holding Registers) and written by Function Code 6(Preset Single Register) or Function Code 16 (Preset Multiple Registers).For example, if this parameter is set to 1000 and a Function Code 3 command isreceived requesting Holding Register address 0 (virtual Modbus address 40001or 400001), the data returned in the response will be the value at register 1000 inthe gateway's database.


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3.1.23 Use Guard Band Timer

YES or NOThis parameter specifies if the Guard Band feature (intercharacter delaymonitoring and control) is to be used or not. Normally, this feature will not be

needed. It is used only when the port is set for Modbus RTU mode as a slavedevice in a multi-drop, multi-node network (RS-422 or RS-485 wiring). If theremote Master experiences multiple, successive failures when trying tocommunicate with the gateway on a multi-drop network, setting a small amountof Guard Band Time will usually completely eliminate the failures.When the port is configured as a slave and when multiple slave nodes exist onthe network (multi-drop), without the Guard Band Timer, the gateway might notbe able to properly discriminate between a response message returned byanother slave and a command from the Master to which it should respond. TheGuard Band Timeoutparameter allows you to set a small delay which can helpeliminate communication errors on the Modbus network.To enable the Guard Band Timeout parameter:

1 First of all, enable the the Use Guard Band Timerparameter.Use Guard Band Timer = Y

2 Then, set the Guard Band Timeout.Guard Band Timeout = 0

This configuration will set the gateway to use a pre-defined time interval forModbus message recognition calculated for each baud rate. This shouldprovide optimal performance for most applications.

If you still observe a considerable number of communication errors, try toincrease the Guard Band Timeoutvalue until the network performance isimproved.


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3.1.24 Guard Band Timeout

0 TO 65535A value of 1 to 65535 sets the time in milliseconds. When this period has elapsedand no further data is received, the gateway will handle the last received data

sequence as a Modbus message to be processed.This parameter specifies the Guard Band Timeoutbetween packets in multi-dropslave mode. A value of 0 uses the default time, which is roughly equivalent to thetime it would take to send 3.5 bytes at the selected baud rate. This is the delayvalue specified by the Modbus RTU protocol specifications.The following GuardBand Timeoutvalues will be automatically used by the gateway when Use GuardBandis set to YES and the Guard Band Timeoutis set to the default value of zero(0).Baud Guard Band Timer (ms)

110 350

150 256

300 128600 64

1200 32

2400 16

4800 8

9600 4

19200 2

28800 2

38400 2

57600 1

115200 1

3.1.25 Minimum Command Delay

0 TO 65535This parameter specifies the number of milliseconds to wait between receivingthe end of a slave's response to the most recently transmitted command and theissuance of the next command. This parameter can be used to place a delayafter each command to avoid sending commands on the network faster than theslaves can be ready to receive them. This parameter does not affect retries of acommand, as retries will be issued when a command failure is recognized.


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3.1.26 Error Delay Counter

0 TO 65535This parameter specifies the number of poll attempts to be skipped before tryingto re-establish communications with a slave that has failed to respond to a

command within the time limit set by the Response Timeoutparameter. After theslave fails to respond, the master will skip sending commands that should havebeen sent to the slave until the number of skipped commands matches the valueentered in this parameter. This creates a sort of slow pollmode for slaves thatare experiencing communication problems.

3.1.27 Command Control Reg

0 TO 3900This parameter allows you to control the execution of commands in theCommand List (page 34) by setting a value of zero (0), one (1), two (2), or three(3) into a 100-register area of the gateway database, beginning at the address

entered in this parameter. If a user defines commands in the list with an Enable(page 35) code of zero for all commands, no commands will execute. If the valuein the first control register is changed to one (1), command zero will executecontinuously. If the value is the control register for a write command is set to two(2), the command will be enabled for conditional writing, which will cause thecommand to execute whenever the values in the database registers associatedwith the command change. Use the value of three (3) only for bit-level writecommands, FC 5 and 15. If the parameter is set to three(3), the command willexecute only if the internal bit data associated with the command changes. It willalso clear the bit or bits in the internal database after the write command is built.This Command Control feature can be disabled by setting this parameter to avalue of-1 or by omitting the item name from the configuration file, resulting the

gateway to using a default value of -1.


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3.2 [Modbus Port X Commands]

The [Modbus Port X Commands] (where X can be 0, 1, 2, or 3) sections of theCFG file are used to define a Master serial port Command List. This list holds theparameters needed to poll slave devices attached to a Master port. The gatewaysupports eight types of commands. This permits the gateway to interface with awide variety of Modbus slave devices.The Command Listis formatted differently than the other sections of theconfiguration file. Commands are present in a block between the labels STARTand END. These labels inform the program where the list resides. The module'sprogram will parse all commands after the START label until it reaches the ENDlabel or until the command count entered for the port is reached.The format of each command in the list is the same. The parameter valuesentered determine the operation to be performed. The following table listssupported Modbus Functions Codes and outlines their format.

Module Information Data Device Information Data

Column

#

1 2 3 4 5 6 7 8

ModbusFunctionCode

EnableCode

InternalAddress

PollIntervalTime

Count SwapCode

SlaveNode

FunctionCode

DeviceMODBUSAddress

FC1 Code Bit Seconds Count 0 Address 1 Bit


FC3 Code Register Seconds Count Code Address 3 Register

FC4 Code Register Seconds Count 0 Address 4 Register


FC6 Code Register Seconds Count Code Address 6 Register

FC15 Code Bit Seconds Count 0 Address 15 BitFC16 Code Register Seconds Count Code Address 16 Register

The first part of the record is the Module Information, which relates to the ProLinxmodule and the second part contains information required to interface to theModbus slave device. Refer to the Modbus protocol specification and slavedevice documentation for a full discussion of each function. The Device ModbusAddress information can be found in the documentation for the slave device.Command list example:

[PORT 0 COMMANDS]# INTERNAL POLL SWAP SLAVE FUNCTION DEVICE# ENABLE ADDRESS INTERVAL COUNT CODE NODE CODE ADDRESSSTART

1 0 0 10 0 1 3 01 0 0 10 0 1 16 10

END


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3.2.1 Enable

0,1,2 or 3This field defines whether the command is to be executed and under whatconditions.

If the parameter is set to 0, the command is disabled and will not be executed inthe normal polling sequence. However, the command can still be activated usingCommand Control.Setting the parameter to a value of 1 causes the command to be executed eachscan of the Command Listif the Poll Intervalis set to zero (0). If the Poll Intervalis set to a non-zero value, the command will be executed, when the interval timerfor that command expires.An Enablecode of 2 is valid only for write commands, FC 5, 6, 15, and 16. If theparameter is set to 2, the command will execute only if the internal dataassociated with the command changes.An Enablecode of 3 is valid only for bit-level write commands, FC 5 and 15. Ifthe parameter is set to 3, the command will execute only if the internal bit dataassociated with the command changes. It will also clear the bit or bits in theinternal database after the write command is built.

Important: Not all revisions of the MCM driver support an Enablecode of 3. Todetermine if your gateway supports this Enablecode, contact ProSoft TechnicalSupport.

3.2.2 Internal Address

0 TO 3999 (for register-level addressing)or

0 TO 63999 (for bit-level addressing)This field specifies the database address in the gateway's internal database touse as the destination for data brought in by a read command or as the sourcefor data to be sent out by a write command. The database address is interpretedas a bit address or a 16-bit register (word) address, depending on the ModbusFunction Code used in the command. For Modbus functions 1, 2, 5, and 15, this parameter is interpreted as a bit-

level address. For Modbus functions 3, 4, 6, and 16, this parameter is interpreted as a

register-level address.

3.2.3 Poll Interval

0 TO 65535This parameter specifies the minimum interval between executions of acontinuous commands (Enablecode of 1). The value is in seconds. Therefore, ifa value of 10 is entered, the command will execute no more frequently than onceevery 10 seconds.


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3.2.4 Reg Count

Regs: 1 to 125Coils: 1 to 800This parameter specifies the number of 16-bit registers or binary bits to be

transferred by the command. Functions 5 and 6 ignore this field as they apply only to a single data point. For functions 1, 2, and 15, this parameter sets the number of bits (inputs or

coils) to be transferred by the command. For functions 3, 4, and 16, this parameter sets the number of registers to be

transferred by the command.

3.2.5 Swap Code

NONESWAP WORDSSWAP WORDS &BYTESSWAP BYTESThis parameter defines if and how the order of bytes in data received or sent is tobe rearranged. This option exists to allow for the fact that different manufacturersstore and transmit multi-byte data in different combinations. This parameter ishelpful when dealing with floating-point or other multi-byte values, as there is noone standard method of storing these data types. The parameter can be set torearrange the byte order of data received or sent into an order more useful orconvenient for other applications. The following table defines the valid SwapCodevalues and the effect they have on the byte-order of the data.

Swap Code Description

NONE No change is made in the byte ordering (1234 = 1234)

SWAP WORDS The words are swapped (1234=3412)

SWAP WORDS &BYTES The words are swapped, then the bytes in each word are swapped(1234=4321)

SWAP BYTES The bytes in each word are swapped (1234=2143)

These swap operations affect 4-byte (or 2-word) groups of data. Therefore, dataswapping using these Swap Codesshould be done only when using an evennumber of words, such as when 32-bit integer or floating-point data is involved.


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3.2.6 Slave Address

0 - Broadcast to all nodes1 to 255Use this parameter to specify the slave address of a remote Modbus Serial

device through a Modbus Ethernet to Serial converter.

Note: Use the Node IP Addressparameter to address commands to a remoteModbus TCP/IP device.Note: Most Modbus devices accept an address in the range of only 1 to 247, socheck with the slave device manufacturer to see if a particular slave can useaddresses 248 to 255.If the value is set to zero, the command will be a broadcast message on thenetwork. The Modbus protocol permits broadcast commands for writeoperations. Do not use node address 0 for read operations.

3.2.7 Modbus Function

1, 2, 3, 4, 5, 6, 15, or 16This parameter specifies the Modbus Function Code to be executed by thecommand. These function codes are defined in the Modbus protocol. Thefollowing table lists the purpose of each function supported by the module. Moreinformation on the protocol is available from www.modbus.org.

Modbus Function Code Description

1 Read Coil Status

2 Read Input Status

3 Read Holding Registers

4 Read Input Registers

5 Force (Write) Single Coil

6 Preset (Write) Single Register

15 Force Multiple Coils

16 Preset Multiple Registers


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3.2.8 MB Address in Device

This parameter specifies the starting Modbus register or bit address in the Slaveto be used by the command. Refer to the documentation of each Modbus Slavedevice for the register and bit address assignments valid for that device.

The Modbus Function Code determines whether the address will be a register-level or bit-level OFFSET address into a given data type range. The offset will bethe target data address in the Slave minus the base address for that data type.Base addresses for the different data types are: 00001 or 000001 (0x0001) for bit-level Coil data (Function Codes 1, 5, and

15). 10001 or 100001 (1x0001) for bit-level Input Status data (Function Code 2) 30001 or 300001 (3x0001) for Input Register data (Function Code 4) 40001 or 400001 (4x0001) for Holding Register data (Function Codes 3, 6,

and 16).Address calculation examples: For bit-level Coil commands (FC 1, 5, or 15) to read or write a Coil 0X

address 00001, specify a value of 0 (00001 - 00001 = 0). For Coil address 00115, specify 114

(00115 - 00001 = 114) For register read or write commands (FC 3, 6, or 16) 4X range, for 40001,

specify a value of 0(40001 - 40001 = 0).

For 01101, 11101, 31101 or 41101, specify a value of 1100.(01101 - 00001 = 1100)(11101 -10001 = 1100)(31101 - 30001 = 1100)(41101 - 40001 = 1100)

Note: If the documentation for a particular Modbus Slave device lists dataaddresses in hexadecimal (base16) notation, you will need to convert thehexadecimal value to a decimal value to enter in this parameter. In such cases, itis not usually necessary to subtract 1 from the converted decimal number, as thisaddressing scheme typically uses the exact offset address expressed as ahexadecimal number.


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MCM ProLinx Gateway Serial Port Modbus Error and Status DataModbus Master/Slave Protocol Manual


4 Serial Port Modbus Error and Status Data

In This Chapter

Viewing Error and Status Data .............................................................. 40

Modbus Error and Status Data Area Addresses .......... ........... .......... ..... 41

Error Codes ........................................................................................... 47

The most thorough troubleshooting method for debugging the operation of theMCM driver (and the gateway in general) is the powerful Debug port on the

gateway. Accessing the Debug capabilities of the gateway is accomplished byconnecting a PC to the Debug port and loading a terminal program such asProSoft Configuration Builder or Windows HyperTerminal.

Note: 4101 series modules that use both serial ports (Debug and Port x) asapplication ports (for example, 4101-MCM-DFCM) must be reset or power-cycledin order to enable the selected port as a Debug port. To enable the debug port,connect to the port using a null-modem serial cable, and then press and hold the[A] key on the keyboard while resetting or power cycling the card. Do not releasethe key until HyperTerminal shows the debug port menu. Debug mode can beenabled on either port. The upload/download command is only available whenconnected to the Debug port.


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4.1 Viewing Error and Status Data

The following topics list the register addresses that contain error and status data.Use the Database View option from the ProLinx Main Menu to view the contentsof each register. The ProLinx Reference Guideprovides additional information onusing this option.


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4.2 Modbus Error and Status Data Area Addresses

Modbus error and status data are stored in registers based on port number.Starting register addresses are shown in the following table.Modbus Port Starting Address

0 44001 4800

2 5200

3 5600

Note: None of the addresses are available in the Modbus address range. Inorder to view them via a Modbus request, they must be moved into the 0 to 3999address range using the Data Map section of the configuration file. For additionalinformation on how to move data within the gateway's internal database, seeMoving Data (page 87).

4.2.1 Modbus Ports: Error and StatusThe serial port (Modbus Master/Slave) Error and Status Data areas arediscussed in this section.The data area is initialized with zeros whenever the gateway is restarted. Thisoccurs during a cold-start (power-on), reset (reset push-button pressed) or awarm-boot operation (commanded from a debug menu or after downloading anew configuration). The addresses listed are for Port 0 only; but the format is thesame for each port. The start address for each port is given in the previoussection, Modbus Error and Status Data Area Addresses (page 41).Example InternalDatabase Address

Offset Description

4400 0 Number of Command Requests4401 1 Number of Command Responses

4402 2 Number of Command Errors

4403 3 Number of Requests

4404 4 Number of Responses

4405 5 Number of Errors Sent

4406 6 Number of Errors Received

4407 7 Configuration Error Code

4408 8 Current Error/Index

4409 9 Last Error/Index

Refer to the following Error Codes (page 47) section to interpret the status/errorcodes present in the data area.


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4.2.2 Slave Port: General Port STATE and COMM STATE Status

In addition to the port status information stored in the gateway database memory,as already mentioned, there are two additional port status parameters that arenot available from the database. The status values, Port STATE (highlighted inyellow) and Port COMM STATE (highlighted in orange), can be found onlythough the diagnostic menus under "Communication Status" for a port, as shownin the following graphic.

These status values are state registers. They are used as 'scratchpad' areas bythe operating firmware to keep track of the current logical state of activities on aslave port. These state registers are constantly changing as the gateway

progresses through the various stages needed to process communication on theserial ports. This processing happens faster than can be followed, unless a porterror causes the value to remain constant for some noticable length of time.


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The diagnostic screen displays are 'snapshot' type screens; that is, they displaythe current value at the time they are called but do not continue to automaticallyupdate the data displayed. They are not live-data screens. Therefore, to see achange in STATE or COMM STATE, you must repeatedly call the screen bypressing the appropriate menu key to have the screen refreshed. Depending on

the refresh timing you may or may not see a change in the displayed valueseverytime you call for an update.The STATE register may display any of the following values.

STATE Value Description

-2 Preparing port, Flushing all buffers, Scan for RTS-Off, or Waiting for port enablesignal

-1 Waiting for receipt of data

0 Undefined state

1 Receiving a message from the Master

2 Building a slave response message

2000 Sending slave response to the Master

The COMM STATE register may display any of the following values.

COMM STATEValue

Description

0 Port not sending data (Wait for send)

1 Setting up minimum Response Delay Timer

101 Waiting for Minimum Response Delay to timeout

2 Turning on RTS line and starting RTS-On Delay Timer

3 Waiting for RTS-On Delay timer to timeout

4 Sending data

5 Waiting for all data to be sent and starting RTS-Off Delay Timer

6 Waiting for RTS-Off Delay timeout and then turning OFF RTS line after timeout

4.2.3 Master Port: Command List Errors

The individual command errors for each Master port are returned to the addresslocations specified in the following table. Each port can have up to 100commands configured. Each configured command will use one word of thesedata areas to store a value representing the execution status from the mostrecent command execution attempt.

Modbus Port Address Range0 4410 to 4509

1 4810 to 4909

2 5210 to 5309

3 5610 to 5709


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The first word in the defined register location contains the status/error code forthe first command in the port's Command List. Successive words in theCommand Error Listare associated with corresponding commands in the list.Refer to Error Codes (page 47) to interpret the status/error codes present in thisdata area.

Port 0 Command Error List Layout

The addresses listed are for Port 0 only; but the format is the same for each port.The start address for each port is given in the previous section, Master Port:Command List Errors (page 43).

Internal DatabaseAddress (Example)

Offset Description

4410 0 Command #0 Error Status





... ... ...

... ... ...

... ... ...




Note that the values in the Command Error Listtables are initialized to zero (0) atpower-up, cold boot, and warm boot. If a command executes successfully, thevalue in the associated register will remain at zero (0), indicating no command

error was detected. Any non-zero value in this table indicates the correspondingcommand experienced an error. The Error Code (page 47) shown will providevaluable troubleshooting information.The data in this table is dynamic. It is updated each time a command isexecuted. Therefore, if the command fails once and succeeds on the nextattempt, the Error Code from the previously failed attempt will be replace withzero and lost. Error Codes are not archived in the gateway's database. To see ifthe port has experienced an error since the most recent restart and what themost recently occurring error was, if any, you can check the Last Error/Index(page 41).


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4.2.4 Master Port: Modbus Slave List Status

The slave status list contains the current poll status of each slave device on aMaster port. Slaves attached to a Master port can have one of three states.

0 The slave has not defined in the command list for the Master port and will not be polledfrom the Command List.

1 The slave is configured to be polled by the Master port and the most recentcommunication attempt was successful.

2 The Master port has failed to communicate with the slave device. Communication withthe slave is suspended for a user defined period based on the scanning of thecommand list.

Slaves are defined to the system when the gateway loads the Master CommandList during start-up and initialization. Each slave defined will be set to a statevalue of 1 in this initial step. If the Master port fails to communicate with a slavedevice (timeout expired on a command, retries failed), the Master will set thestate of the slave to a value of 2 in this status table. This suspendscommunication with the slave device for a user-specified Error Delay Count

(page 33).When the Master first suspends polling of a particular slave, it creates a ErrorDelay Counter for this slave address and set the value in that counter equal tothe Error Delay Counter parameter in the configuration file. Then, each time acommand in the list is scanned that has the address of a suspended slave, thedelay counter value for that slave will be decremented. When the value reacheszero, the slave state will be set to 1. This will re-enable polling of the slave.The first word in the defined register locations contains the status code for slavenode address 1. Each successive word in the list is associated with the nextnode in sequence, up to slave node address 255.The individual Slave List Status for each Modbus port are returned to the addresslocations specified in the following table.Modbus Port Address Range

0 4510 to 4764

1 4910 to 5164

2 5310 to 5564

3 5710 to 5965=4


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Port 0 Slave List Status Layout

The addresses listed are for Port 0 only; but the format is the same for each port.The start address for each port is given in the previous section, Master Port:Modbus Slave List Status. (page 45)

InternalDatabaseAddress(Example)

Offset Description

4510 0 Slave #1 Status





. .

. .

. .

Note that the values in the Slave List Status tables are initialized to zero (0) atpower-up, cold boot and during warm boot.


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4.3 Error Codes

These are error codes that are part of the Modbus protocol or are extendedcodes unique to this gateway.

4.3.1 Modbus Error CodesThese error codes are generated or returned on both the Master and slave ports.These codes are the standard Modbus errors (page 84).Code Description

1 Illegal Function

2 Illegal Data Address

3 Illegal Data Value

4 Failure in Associated Device

5 Acknowledge

6 Busy, Rejected Message


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4.4 Module Communication Error Codes

These gateway-specific error codes are also returned from the command pollingprocess and stored in the Command Error List memory area.

Code Description

-1 CTS modem control line not set before transmit

-2 Timeout while transmitting message

-11 Timeout waiting for response after request

253 Incorrect slave address in response

254 Incorrect function code in response

255 Invalid CRC/LRC value in response

4.4.1 Command List Error Codes

These command-specific error codes are detected during initial command list

loading at gateway power-up or reset and are stored in the Command Error Listmemory region.CODE Description

-41 Invalid enable code

-42 Internal address > maximum address

-43 Invalid node address ( 255)

-44 Count parameter set to 0

-45 Invalid function code

-46 All parameters set to 0

-47 All parameters set to -1


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4.4.2 Modbus Configuration Error Word

Modbus Configuration Error Word values are stored in protocol-specific registers.The following table lists the register address used for each port that may exist onthe gateway.

Modbus Port Configuration Error Word Register0 4407

1 4807

2 5207

3 5607

If any of these registers contains a non-zero value, it indicates a problem with theconfiguration of the associated port. The following table lists the codes, adescription of the problem, and which parameters to change tocorrect the errorcondition within the configuration file.Bit Code Description

0 0x0001 Invalid Enabled parameter (Yes or No)

1 0x0002 Invalid RS-Interface parameter (0 to 2)2 0x0004 Invalid Type (Master or Slave)

3 0x0008 Invalid Protocol (RTU or ASCII)

4 0x0010 Invalid Baud Rate

5 0x0020 Invalid Parity (None, Odd, Even)

6 0x0040 Invalid Data Bits (7 or 8 bits)

7 0x0080 Invalid Stop Bits (1 or 2)

8 0x0100 Invalid Use CTS Line (Yes or No)

9 0x0200 Retry Count Invalid (0 to 10)

10 0x0400 Invalid Floating Point Data:

Float Flag not Yes or NoFloat Start less than 0 orFloat Offset is Invalid

11 0x0800 Invalid Internal Slave ID (1 to 255) (Slave Only)

12 0x1000 Invalid Entry for Register Offset Data (Slave Only)

13 0x2000 Reserved

14 0x4000 Reserved

15 0x8000 Reserved


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MCM ProLinx Gateway Communication Port CablesModbus Master/Slave Protocol Manual


5 Communication Port Cables

This section contains information on the cable and pin assignments for theProLinx gateway's serial ports (RS-232/422/485). The ProLinx gateway will comewith one to five serial ports, depending on the configuration purchased. In allcases, the protocol serial ports will have the same pinouts.

Example: The 5202-MNET-MCM4 gateway contains five serial communicationports; four configurable protocol application ports and one Configuration/ Debugport.The 5201-MNET-MCM gateway contains two serial communication ports; oneconfigurable protocol application port and one Configuration/Debug port.

Each physical serial port has an eight-pin Mini-DIN jack connector. A six-inchMini-DIN-8Male to DB-9Male adapter cable is provided for each serial port. TheDB-9M provides connections for RS-232, wired as Data Terminal Equipment(DTE), RS-422 and RS-485. The diagrams in the following topics detail the pinassignments for several possible electrical interface connections.


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Communication Port Cables MCM ProLinx GatewayProtocol Manual Modbus Master/Slave


5.1 Port 0, 1, 2, 3: RS-232 - Null Modem (DTE with HardwareHandshaking)

This type of connection is used when the device connected to the gatewayrequires hardware handshaking (control and monitoring of modem signal lines;Use CTS(page 28) parameter set to YES).


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5.2 Port 0, 1, 2, 3: RS-232 - Null Modem (DTE without HardwareHandshaking)

This type of connection can be used to connect the gateway to a computer orfield device communication port.

Note: If the port is configured with the Use CTS(page 28) set to YES, then ajumper is required between the RTS and the CTS line on the gatewayconnection.


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5.3 Port 0, 1, 2, 3: RS-232 - DTE to DCE Modem Connection

This type of connection is required between the gateway and a modem or othercommunication device.

The Use CTS Line(page 28) parameter for the port configuration should be setto YES for most modem applications.


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5.4 Port 0, 1, 2, 3: RS-422 Interface Connections

The following illustration applies when the RS-422 interface is selected.


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5.5 Port 0, 1, 2, 3: RS-485 Interface Connections

The following illustration applies when the RS-485 interface is selected.

NOTE: This type of connection is commonly calleda RS-485 half-duplex, 2-wireconnection. If you have RS-485 4-wire, full-duplex devices, they can beconnected to the gateway's serial ports by wiring together the TxD+ and RxD+from the two pins of the full-duplex device to Pin 1 on the gateway and wiring

together the TxD- and RxD- from the two pins of the full-duplex device to Pin 8on the gateway. As an alternative, you could try setting the gateway to use theRS-422 interface and connect the full-duplex device according to the RS-422wiring diagram (page 55). For additional assistance, please contact ProSoftTechnical Support.


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6 LED Indicators

In This Chapter

Base Module LEDs ................................................................................ 58

LEDs for Serial Ports ............................................................................. 59

LED indicators provide a means of monitoring the operation of the system andindividual ports. There are extremely useful for troubleshooting. The gatewayprovides LEDs to help monitor each port. In addition, system configuration errors,application errors, and fault indications are all indicated by LEDs, providing alertsto possible problems.


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6.1 Base Module LEDs

LED State Description

Power Off Power is not connected to the power terminals or source is insufficientto properly power the gateway (minimum required is 800mA at 24 Vdc)

Green Solid Power is connected to the power terminals.Fault Off Normal operation.

Red Solid A critical error has occurred. Program executable has failed or hasbeen user-terminated and is no longer running. Press Reset p/b orcycle power to clear error. If not, use the Debug procedures describedlater in this manual.

Cfg Off Normal operation.

Amber Solid The unit is in configuration mode. The configuration file is currentlybeing downloaded or, after power-up, is being read, the unit isimplementing the configuration values, and initializing the hardware.This will occur during power cycle, or after pressing the reset button. Italso occurs after a cold/warm boot command is received.

Err Off Normal operation.

Flashing An error condition has been detected and is occurring on one of theapplication ports. Check configuration and troubleshoot forcommunication errors.

Solid Red This error flag is cleared at the start of each command attempt(Master/Client) or on each receipt of data (slave/adapter/server); so, ifthis condition exists, it indicates a large number of errors are occurringin the application (due to bad configuration) or on one or more ports(network communication failures).


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6.2 LEDs for Serial Ports

ProLinx gateways may have as many as five (5) serial ports. Each of these serialports has two LEDs indicating status.LED Color Description

Debug - ACTPort 0 - ACTPort 1 - ACTPort 2 - ACTPort 3 - ACT

Off No activity on the port.GreenFlash

The port is actively transmitting or receiving data

Debug - ERRPort 0 - ERRPort 1 - ERRPort 2 - ERRPort 3 - ERR

Off Normal state. When off and Port Active led is indicatingactivity, there are no communication errors

REDOn Solid orFlashing

Activity on this LED indicates communication errors areoccurring. To determine the exact error, connect the Debugterminal to the Debug port and use the built-

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