Emerson PACSystems VersaMax IC200CMM020 User manual

IMPORTANT PRODUCT INFORMATION
GFK-2423G
Nov 2019
PACSystemsTM VersaMax
SERIAL COMMUNICATION MODULE
(IC200CMM020)

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Warning Notes as Used in this Publication
Warning
Warning notices are used in this publication to emphasize that hazardous voltages, currents,
temperatures, or other conditions that could cause personal injury exist in this equipment or
may be associated with its use.
In situations where inattention could cause either personal injury or damage to equipment, a
Warning notice is used.
Notes: Notes merely call attention to information that is especially significant to understanding and operating the equipment.
These instructions do not purport to cover all details or variations in equipment, nor to provide for every possible
contingency to be met during installation, operation, and maintenance. The information is supplied for informational
purposes only, and Emerson makes no warranty as to the accuracy of the information included herein. Changes,
modifications, and/or improvements to equipment and specifications are made periodically and these changes may or
may not be reflected herein. It is understood that Emerson may make changes, modifications, or improvements to the
equipment referenced herein or to the document itself at any time. This document is intended for trained personnel
familiar with the Emerson products referenced herein.
Emerson may have patents or pending patent applications covering subject matter in this document. The furnishing of
this document does not provide any license whatsoever to any of these patents.
Emerson provides the following document and the information included therein as-is and without warranty of any kind,
expressed or implied, including but not limited to any implied statutory warranty of merchantability or fitness for
particular purpose.

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Product Description
The VersaMax Serial Communications Module, IC200CMM020, operates as a Modbus RTU Master in a VersaMax I/O
Station controlled by a Genius Network Interface Unit or a PROFINET Scanner.
Serial Communications Modules may be installed at any location in the I/O Station. Up to two Serial Communications
modules can be used per I/O Station.
Genius NIU
Optional booster
power supply
Serial Communications
Module
The module will support communication baud rates of 1200, 2400, 4800, 9600, and 19200, and half or full duplex
operation.
Serial Communications Port
The RS-485 serial port is a 15-pin subminiature ‘D’ connector. For RS-232 communications, an RS-485 to RS-232 adapter
such as IC690ACC901 can be used. Adapter IC690ACC901 can be installed with its right-angle cable hanging down.
Serial Port Pin Assignments
Pin
Signal
Direction
Function
1
Shield
--
Shield drain wire connection
2
NC
3
NC
4
ATTACH
Input
5
P5V
Output
5V to power external adapters
6
RTS(A)
Output
Request-to-Send (A) output
7
0V
--
Ground reference
8
CTS(B)
Input
Clear-to-Send (B) input
9
RT
--
Termination for RDA
10
RD(A)
Input
Receive Data (A) input
11
RD(B)
Input
Receive Data (B) input
12
SD(A)
Output
Transmit Data (A) output
13
SD(B)
Output
Transmit Data (B) output
14
RTS(B)
Output
Request to Send (B) output
15
CTS(A)
Input
Clear to Send (A) input
Shell
Shield
--
Shield for 100% (continuous) coverage
This port supports both 2-wire and 4-wire electrical interfaces:
•Two-Wire Interface (single shielded twisted pair, half-duplex mode only) –Connect D1 to RD(A) at pin-10, D0 to
RD(B) at pin-11, and the shield to frame ground at pin-1.
•Four-Wire Master Interface (two shielded twisted pairs, full-duplex mode) –Slaves receive data from the RTU
master over the MODBUS master pair RXD1 & RXD0. At the same time, the RTU receives data from the slaves over
the MODBUS slave-pair TXD1 & TXD0. Connect RXD1 to SD(A) at pin-12, RXD0 to SD(B) at pin 13, TXD1 to RD(A)
at pin 10, TXD0 to RD(B) at pin 11, and both shields to the frame ground at pin 1.

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5V Power
The module supplies 5V power to external devices via the serial port. The amount of power available to external devices
is approximately 100mA, and varies depending on how the serial device(s) are wired. The module itself requires 10mA,
and a half-duplex line terminated with 120 Ohms at each end requires an additional 83mA. The actual current draw
depends on serial line terminations, duplex mode, serial line activity, and use of external adapters that may require
additional 5V power. (This module does not use 3.3V.)
If the total load exceeds 200mA, an internal current-limit switch prevents damage and shuts down serial
communication and external power flow. The module’s OK LED will be amber. The user must alleviate the overdraw
condition. Communication and power flow will resume when the condition is resolved.
Specifications
Number of Serial Communications
Modules
Maximum: 8 per VersaMax Profinet Scanner (PNS)
Maximum: 2 per Genius NIU I/O Station
Number of RTU slaves per Serial
Communications Module
1 to 247
COMMREQ command memory (%AQ)
required in the GENERIC_COMM module
hardware configuration
Depends on individual COMMREQ content.
Minimum: 22 words Maximum: 64 words
COMMREQ response memory (%AI)
required
Minimum: 2 words
Maximum: 64 words
RTU Master Commands
As described in Modbus RTU Communications Manual, GFK-2220. Minor differences as
described below.
65520, Initialize RTU Master Port
8000, Clear RTU Master Diag. Status
8001, Read RTU Master Diag. Status
8002, SendRTURead/Force/PresetQuery
8003, Send RTU Diagnostic Query
The minimum of 22 words is the required amount of memory that needs to be configured in the GENERIC_COMM
module configuration to execute the Initialize RTU Master Port Command (65520). The minimum for all other
commands is dependent on the size of the command and the amount data requested (if any).
Preinstallation Check
Carefully inspect all shipping containers for damage. If any equipment is damaged, notify the delivery service
immediately. Save the damaged shipping container for inspection by the delivery service. After unpacking the
equipment, record all serial numbers. Save the shipping containers and packing material in case it is necessary to
transport or ship any part of the system.
Quick Start Guide
1. Install the Communications Carrier on the DIN Rail by simply clicking it into place.
Note: Connecting carriers must be installed on the same section of 35mm x 7.5mm DIN rail. The DIN rail
must have a conductive (unpainted) finish for proper grounding

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2. Install the Module on the Communications Carrier.
The latch on the module must be in the unlocked position
Align the connectors and the latch post and press the module down until the two tabs on the bottom
of the module click into place.
Turn the latch to the locked position to secure the module to the top of the carrier.
3. Connect the communications bus to the connector on the front of the module.
4. Remove the connector cover on the right-hand side of the Communications Carrier. Do not discard this cover;
you will need to install it on the last carrier. It protects the connector pins from damage and ESD during handling
and use.
Connector
Cover
5. Install additional modules by mounting modules on their carriers and sliding them along the DIN rail to fully
engage the connectors in the sides of the carriers.
6. Power up the System, and Observe the Module LEDs. The LEDs indicate the presence of power and show the
operating mode and status of the module.
MOD
OK
PORT
ACT
OK
OFF when the module has not yet started its powerup sequence.
Green indicates the module has successfully completed powerup diagnostics.
Amber means the module has detected overpower condition. No powerflow or communication activity will take
place.
Blinking amber means the module has failed powerup diagnostics. The number of blinks indicates the fault type.
Blinking green indicates the module is in boot mode or its firmware is being updated.
MOD
OFF when the module is not powered.
Green when the module is operating normally.
Blinking amber indicates the module configuration is missing, incomplete, or incorrect.
PORT
ACT
OFF when the module is not powered or no communication activity is occurring. For example, communication
activity will not occur during an overpower condition.
Blinking green indicates the module is online and communicating.

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Installation in Hazardous Locations
•This equipment is suitable for use in CLASS I, DIVISION 2, GROUPS A, B, C, D or non-hazardous locations only.
WARNING
•EXPLOSION HAZARD - substitution of components may impair suitability for CLASS I, DIVISION 2;
•EXPLOSION HAZARD - when in hazardous locations, turn off power before replacing or wiring modules; and
•EXPLOSION HAZARD - Do not connect or disconnect equipment unless power has been switched off or the area
is known to be non-hazardous.
Configuration
In VersaMax PROFINET IO device in an RX3i PROFINET network, the Serial Communications module is configured by
selecting it from the PROFINET Scanner submodule list in the programming software. For details, see the PACSystems
RX3i PROFINET Controller Manual, GFK-2571.
In a VersaMax Genius network, the VersaMax Serial Communications module is configured using the GENERIC_COMM
configuration feature of the programmer.
Initially, the module’s default Reference Addresses for %AI and %AQ data have a length of zero. These data lengths must
be changed, as shown in the example Proficy Machine Edition v5.50 screen illustrated below, before the module can
communicate with the Ethernet NIU. The %I and %Q lengths must stay zero. The module cannot communicate on the
serial network until it receives a valid configuration.
Enter the value 10 for the module ID when configuring the module as a “GENERIC_COMM” module in the Genius NIU
system. The “GENERIC_COMM” module configuration will display the value “FFFF980A” for the Module ID parameter
Modbus RTU Communications
The VersaMax Serial Communications module supports Modbus RTU Master protocol. To operate as a Master, the Serial
Communications module must receive commands from a remote host. For example, the remote host could be an RX7i
PLC that communicates with the I/O Station’s VersaMax Genius NIU via a Genius Bus Controller module.
Receiving Commands from a Remote Host
The Serial Communications module exchanges commands with the remote host via the input and output memory areas
of the I/O Station’s Genius NIU. The commands used for these communications are referred to as “memory mapped
COMMREQs” because their format is similar to the existing Modbus RTU COMMREQ (Communication Request)
commands. These commands are defined in the document Modbus RTU Communications, GFK-2220C or later, which
is available at https://www.emerson.com/Industrial-Automation-Controls/support.
Commands from the remote host to the module are sent via %AQ memory. The module returns the command response
in the first two %AI registers that have been configured for the module. The content of the command status response is
shown below.
%AI Word Location
Description
Word 1
Command Status Word

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%AI Word Location
Description
Word 2
Sequence Number of
Command
Word 3-n
Data (if any)
Because the status information is mapped into memory, the COMMREQ status address segment selector (Word 3) and
offset (Word 4) in the COMMREQ command block are ignored.
The module forms the requested RTU Master command and exchanges data with an RTU Slave device. The data is
returned to the remote host starting at the third %AI register configured for the module (see table above).
The status values used for the Command Status Word are identical to the values listed in the Modbus RTU
Communications Manual, with one additional status value added to indicate that the module is ready to receive
commands.
Major Error
Code
Minor
Error
Code
Numeric
Status
Value
Description
COMMAND_READY
None
0002h
The RTU Master
is ready to
accept I/O
commands.
Flow Control and Command Sequencing
The remote host’s application program initiates a COMMREQ by executing a COMMREQ function block to the
communication module in the remote host such as a RX7i PLC. The communication module then sends the COMMREQ
block as data to the Genius NIU. At the remote host, the COMMREQ function block causes the COMMREQ
command/data block to be sent to the module once each time the COMMREQ is executed.
When the Genius NIU receives the incoming command/data block, it sends the block to the Serial Communications
Module during the next output scan. The memory-mapped command uses a sequence number in the second word of
the COMMREQ structure (the NOWAIT mode parameter) to indicate that a new command has been sent. After power-
up, the module indicates when it is ready to receive commands by returning a Command Status Word value of
“COMMAND_READY”. Until the module is ready to receive commands, changing the sequence number has no effect.
Once the module has issued a status value of “COMMAND_READY”, any change to the value of the sequence number
prompts the module to process the current command in the module’s %AQ memory. The application program can send
the command multiple times by simply changing the sequence number.
The sequence number value of zero has a special meaning –it is interpreted as a request to clear the module’s input
values. Upon receipt of a 0 sequence number, the CMM020 will check if the entire %AQ memory area is set to zero. If
so, the module’s %AI memory area will be cleared and the “COMMAND_READY” value will be returned in the status.
Note: Any time the Genius NIU is not receiving data from the Genius Bus Controller, it sends default data (all zeroes) to
the CMM020. Therefore, the default data is interpreted as a “clear” request.
Note that if there is non-zero data in the PLC CPU’s %AQ memory when the Genius NIU powers up, that data will be
transferred to the CMM020 after the Genius NIU joins the Genius Bus. Since the initial default data sent to the CMM020
is all zeroes, the non-zero data is interpreted as a command. This may result in behavior that the application creator did
not intend.
The Serial Communications module will only process one command at a time. Therefore, the remote host’s application
program must monitor the sequence number location in %AI memory for the return of the sequence number sent with
the command. After the module returns the sequence number, the program logic should check the status value
returned in %AI memory before sending a new command. The module ignores any new commands that have been sent
by incrementing the sequence number before the command is completed. Likewise, no new command is sent to the
module until the sequence number is changed. When the current command is complete, the module will again process
incoming commands when the sequence number is changed.

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Example
In this example, an application program in a host PLC initializes the Master Serial Port Command Program Block, then
sets up the Send RTU Preset Query Command (08002).
In the host PLC, the Genius Bus Controller is configured at %AQ0001. In the I/O Station, the VersaMax Serial
Communications module is configured in the Genius NIU to have 48 %AQ references starting at %AQ0001 and 32 %AI
references starting at %AI0001. In this example, the AQ memory reference offsets in the PLC are the same as those used
in the Genius NIU. However, that is not necessary.
Note that no commands are sent until reference %AI0001 in the I/O Station’s Genius NIU indicates the Command Ready
Status value of 2.
Part 1: Initialize the Master Serial Port Command Program Block
First, the serial port is configured with the Initialize Master Serial Port Command (65520)
•COMMREQ status value: Zero
•Sequence Number: set to current sequence value (%AQ0002)
•Protocol: Modbus RTU
•Mode: Master
•Data rate: 9,600 bits/Sec.
•Parity: Even
•Flow control: None
•Turnaround delay: Zero
•Response message time-out: STANDARD (0.5 Sec.)
•Bits per Character: 8 (Not configurable)
•Stop Bits: 1 (Not configurable)
•Port Interface: (Not configurable)
•Half-Duplex Mode: 2-Wire
•Character-gap time-out: Default
•RTS Drop Delay: Zero

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To trigger the command, the sequence number, %AQ0002 must be incremented.
When the sequence number in %AI0002 matches the value sent in %AQ0002, it checks the command status value. If
the command status value in %AI0001 is 1, the command has been successfully executed. The Serial Comm Module is
configured as an RTU Master and ready to accept Modbus RTU commands.
Part 2: Set Up the Send RTU Preset Query Command (08002)
COMMREQ status value: Zero
•Sequence Number: set to current sequence value (%AQ0002)
•Address: RTU Slave Address 3
•RTU Function Code: 16
•RTU Data Address: 101
•Number of Data Points: 1
•Data: 0x1234

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As before, to trigger the command, the sequence number, %AQ0002 must be incremented.
When the sequence number in %AI0002 matches the value sent in %AQ0002, it checks the command status value. If
the command status value in %AI0001 is 1, the command has been successfully executed. The Serial Communications
Module has successfully transmitted the Modbus RTU command to RTU Slave Device 3.
RTU Master Commands Supported
The Serial Communications module supports RTU Master command numbers 65520, 8000, 8001, 8002, and 8003 as
described in the Modbus RTU Communications Manual, GFK-2220, with a few differences as described below.
Command 65520 –Initialize RTU Master Port
If it is necessary to change the serial port settings from the default values, the Initialize RTU Master Port command can
be sent to the Serial Communications module by placing the values shown below into the module’s configured %AQ
memory references. The module returns the status of the request in the first word of its configured %AI memory
references and the command’s sequence number in the second word.