1-919-535-3180 | 1-800-360-6802

GE / IP FANUC Series 90/30 In Stock

World's Largest Warehouse

of GE 90-30, Genius, and RX7i



Mon-Fri 8AM-5PM EST



RX3i CMM004 Communication

Rated 4.7/5 Based on 17 ratings.

Rate your purchase of the IC695CMM004

SKU 2173123  UPC 0546718185535


Order Today - Ships Today!

*US continental orders placed Monday-Friday before 4:30pm EST!



7 In Stock

✓  2 Year PDF Supply Warranty

*Need a Specific Revision?

New Surplus


2 In Stock

✓  3 Year PDF Supply Warranty

*What is New Surplus?



3 In Stock

✓  2 Year PDF Supply Warranty

*What is Remanufactured?

Repair Service


5-10 Days

✓  2 Year PDF Supply Warranty

*What is Fast Repair?

Common misspellings:
  • 1C695CMM004
  • IC695CMMo04
  • IC695CMM0o4
  • IC695CMM00A
  • IC695CMM004

Technical Specifications for IC695CMM004

ManufacturerGE Fanuc
SeriesRX3i PACSystems
Part NumberIC695CMM004
Product TypeSerial communication module
Hot SwappableYes
ProtocolsRS-232, RS-485, RS-422
Baud Rate1200 to 115.2 kilobaud
Power Requirement0.7 Amps at 3.3 Volts DC, 0.15 Amps at 5 Volts DC

Product Description

The IC695CMM004 is a Serial Communications module from the GE Fanuc RX3i Series.  This module provides 4 independent, isolated serial ports.  Up to 6 Serial Communications modules can be located in the main PACSystems RX3i backplane.  See specifications for this unit on IC695CMM004's website page.

Technical Specifications

Module Type: Serial Communications
Number of Slots: 1 (single slot)
Backplane Support:   Universal Backplane
Protocol Support: Modbus Master/Slave DNP 3.0/Slave CCM and Custom 
Communication Ports:   (4) Isolated RS-232 or RS485/422
Internal Power: 0.150A @ 5 VDC, 0.7A @ 3.3 VDC


The RX3i PACSystems IC695CMM004 module from GE Fanuc is a serial communication module. Eight independent and isolated serial ports are available on the module. A maximum of 6 serial communications modules can be installed in an RX3i PACSystems chassis. Each port on the module can be configured as Modbus slave, Modbus master, or Serial I/O port. For version 1.10 or later modules, the ports can also be configured as CCM slave ports. For version 1.20 or later modules, the ports can be configured as DNP3 master or slave ports. Features of the IC695CMM004 module include software configurable RS-232, RS-485, and RS-422 serial communication, baud rates ranging from 1200 to 115.2 kilobaud, fault status reporting, port to backplane isolation, and upgradable firmware. Full duplex and half duplex operation is supported for the RS-485/422 protocols.

The IC695CMM004 module complies with the ATEX, CE, 1604, and UL/CUL standards and requirements. The IC695CMM004 module can be inserted and removed while the chassis power is on. The software which can be used to configure the module is the Proficy Machine Edition Logic Developer version 5.6 or later software. The physical interface for the serial ports is the RJ-45 interface. The power requirements of the module are 0.7 Amps at 3.3 Volts DC and 0.15 Amps at 5 Volts DC. The maximum overvoltage rating is +/-25 Volts. The minimum channel-to-channel crosstalk is -55 dB. The port to backplane isolation is 250 Volts AC continuous. The port to port isolation is 500 Volts DC continuous and 710 Volts DC for up to 1 minute. The module operating temperature range is 0 to 60 degrees Celsius.

Technical Information



Number of Serial Ports

IC695CMM002: two independent serial ports IC695CMM004: four independent serial ports



Number of Serial Communications Modules per CPU

Six in the main CPU backplane

Backplane  power requirements


0.7 Amps maximum @  3.3Vdc

0.115 Amps maximum @ 5.0Vdc


0.7 Amps maximum @  3.3Vdc

0.150 Amps maximum @ 5.0Vdc


Module OK, Port Fault, Port Status (2 or 4)

Port Type

RS-232 or RS-485/22. 4-wire (full duplex) or 2-wire (half-duplex) operation for RS-485/422

Flow Control for RS-232

Selectable: Hardware (RTS/CTS, RFR/CTS) or  none

Baud rates

1200, 2400, 4800, 9600, 19.2K, 38.4K, 57.6K, 115.2k


Even, odd, none

Data bits

7, 8

Stop bits

1, 2

Operating Temperature

0ï‚°C to + 60ï‚°C

Input  Impedance

Zin > 96 k for RS-485/422 3 k < Zin < 7 k for RS-232

Max Overvoltage


Channel-Channel Crosstalk

–55dB minimum


Port to Backplane and to frame ground: 250Vac continuous; 1500Vac for 1 minute, 2550Vdc for  one second.

Port to port: 500Vdc continuous, 710Vdc for one  minute.


Troubleshooting IC695CMM004

Troubleshooting information is available on IC695CMM004's website page; it also includes a datasheet user-manual and a wiring diagram.


Repair your IC695CMM004

PDF Supply can repair your IC695CMM004 in 3-5 business days. And PDF Supply stands by all of its repairs with a 1 year customer satisfaction warranty.


How to Optimize Communication With The IC695CMM002/004


IC695CMM002/004 allows the RX3i to work as Master in Modbus communications. Depending on how the configuration or programming have been done, the performance of communications can be acceptable or slower.


Some tips regarding how to optimize the communications:


  • Group the information in the remote device minimizes the number of exchanges. This have two benefits:

- As the number of exchanges are limited to 64 per port, there will more exchanges available for additional remotes devices

- the communication frames take almost the same time, querying for one word than for the maximum allowed.

  • When possible, use Read/Write Single Bit Control. This allows to manage when the program will trigger the communication frame and it is possible prioritize some exchanges. In addition, if an error has been detected in the remote station, the program can avoid to set the bit, prioritizing communications for other active devices.
  • Avoid using Continuous Write/Read. The CPUs does not control this exchange. So if the remote device is off, all the other exchanges will be delayed until the Timeout error happens. Except if the remote target needs to be written every time, it does not make sense to write always if the data in the master have not changed
  • As an intermediate solution Read/Write Continuous Bit-Control can be used. They allow the program to trigger or stop the exchange when needed. So it makes easier to control the exchange but it allows to stop the exchange if the remote device is off.
  • If the module is expecting to receive data and it hasn't received data before this assigned timeout period, a receive timeout error occurs for the exchange being processed. Set a Timeout according to the communications system and baud rate. ie. for wiring systems 1 sec can be enough; radio systems are usually slower, so greater values should be chosen.

IC695CMM002/004 and Modbus RTU Protocol Weakness


The implementation of the Modbus RTU protocol on the CMM002/004 module utilizes the specified 3.5 character silence to recognize an end of message. ; Since radio systems are notorious for dropping characters and injecting delays in the data stream, this can cause significant problems that care must be taken to avoid, when designing the system. Below is an explanation of how data can be placed into the wrong memory location due to dropped bytes and time delays injected into byte streams. See the detailed case study below:

First of all it is critical to understand that the Modbus RTU protocol is specified in such a manner that the response to a Read Holding Register request(or any other request for that matter) has no identifying information other than the Station ID, Function Code, and Data Length. This is a protocol weakness. Feel free to visit the Modbus.org website and download the protocol specification for the protocol details.

Consider this scenario:.

  1. Master sends read %R101, length 100 - radio delivers in tact
  2. Slave replies with 200 bytes of data (it is important to note there is no address in this response)- radio delivers in tact
  3. Master moves data to %R101-200
  4. Master sends read %R201, length 100
  5. Slave replies with 200 bytes of data (it is important to note there is no address in this response)- radio delivers in tact
  6. Master moves data to %R201-300
  7. Master sends read %R301, length 100
  8. Slave replies with 200 bytes of data (it is important to note there is no address in this response)- radio drops bytes and introduces 6 ms Delay thus braking the frame
  9. Master sees broken frame, raises RTS, gets CTS back, clears receive buffer, logs error and sends read %R401 length 100 - radio delivers intact
  10. Master sees second part of broken frame as a response to the %R401 read, sees it as an error (one could argue for length error or CRC error but either way it is seen as a bad response), master sends read %R501 length 100 - radio drops bytes or adds delay in request THEREFORE SLAVE NEVER SEES REQUEST FOR %R501, HOWEVER
  11. Master almost immediately sees response (which happens to be the response to the read of %R400), and of course has no idea of the address due to the protocol limitation and correctly places the 200 bytes received into the outstanding request to read %R501 into memory.(note that the request for %R401 has already failed and been cleared and reported as an error) This is where the protocol limitation becomes an issue. This is not a GE IP issue on the CMM card at this point, because it acted appropriately given the data stream provided by the radio.
  12. Master sends read %R601 length 100 - radio delivers intact
  13. Slave replies with 200 bytes of data (it is important to note there is no address in this response)- radio delivers in tact
  14. Master moves data to %R601-700
  15. Master sends read %R701 length 100 - radio delivers intact
  16. Slave replies with 200 bytes of data (it is important to note there is no address in this response)- radio delivers in tact
  17. Master moves data to %R701-800

Notice that in steps 9 and 10, there are two back to back failures of the radio system in the sense that it was not able to deliver the response message intact and when the next request was made, it was not able to deliver that request intact to the slave. This is one scenario that could lead to data being placed in the wrong register memory.


There are a couple of ways to prevent this from occurring.

1) Do not send multiple back to back requests to the same slave, of the same function code, and data length. If the data length is changed, any response with the correct data length, due to dropped bytes, would not pass the CRC check.

2) Alternate slave id's and function codes for each slave, as these will be unique identifiers contained in any response in the protocol. In other words, if the master were waiting for a response from slave x for function code x, and it sees a response from slave y with function code y, the master will recognize the slave and/or function code as being different from the outstanding request and terminate it with an error.

3) Write logic to control the master request timing, and monitor each request result in order to programmatically insure enough time has passed to prevent such a timing error, since the master should clear its receive buffer before sending a new request and thus again avoid the protocol limitation.

4) Read data into intermediate memory and provide unique identifiers in the data stream that can be used in logic to move the data to the proper location. Although this method may take the most effort, it is the most reliable way to be sure the data is placed in the correct reference memory on a response by response basis. In this case, even if the response were to a different request, your header information in the data stream could include the responding slave number and memory type and length so that your program can properly distribute the data. In fact, this method provides a form of data correction in the sense that a misinterpreted response will be placed in the correct memory location rather than being thrown away causing further delays in updating the data. Similar methods can be used to broadcast slave data as well, increasing your throughput by reducing the number of writes.

Customer Questions and Answers

  • Question:  What is an IC695CMM004?  Answer:  The IC695CMM004 is a Serial Communications module from the GE Fanuc RX3i Series.
  • Question:  What does IC695CMM004 do to the RX3i system?  Answer:  This module expands the serial communications capabilities of the RX3i system.
  • Question:  What does IC695CMM004 provide?  Answer:  This module provides 4 independent, isolated serial ports. 
  • Question:  How many modules can be located in the main PACSystems RX3i backplane?  Answer:  Up to 6 modules can be located in the main backplane.
  • Question:  What can the configuration be for each port?  Answer:
    • Each port can be configured for MODBUS Master, MODBUS Slave, or Serial I/O protocol.
    • For modules that are version 1.10 or later, each port can be configured for CCM Slave protocol using Proficy Machine Edition 5.6, SIM 6 or later.
    • For modules that are version 1.20 or later, each port can be configured for DNP3 Master or DNP3 Slave protocol using Machine Edition 5.6 SIM 10 or later.
    • If any port is configured for DNP3 Master or Slave, the other ports on the module can only be configured for DNP3 Master or Slave.
  • Question:  What are additional features on IC695CMM004?  Answer: 
    • Port-to-port isolation and port-to-backplane isolation
    • RS-232, RS-485/422 communication, software-selected
    • Hardware handshake: RTS/CTS for RS-232
    • Selectable Baud Rates: 1200, 2400, 4800, 9600, 19.2K, 38.4K, 57.6K. 115.2K
    • Module fault status reporting (Watchdog, Ram Fail, Flash Fail)
    • Module identity and status reporting, including LED status indicators
    • Meets CE, UL/CUL 508/1604, and ATEX requirements
    • Flash memory for future upgrades
  • Question:  Where must IC695CMM004 be located?  Answer:  IC695CMM004 must be located in an RX3i Universal Backplane. 
  • Question:  What should I do if my IC695CMM004 is not working properly?  Answer:  Your IC695CMM004 may need repair.

For more information on the IC695CMM004 Serial Communications Module of the GE Fanuc RX3i Series, please see the Datasheet User-Manual.

Release History


Firmware Version

Upgrade Kit


IC695CMM002-EG IC695CMM004-EG



This HW/FW change addresses a component obsolescence issue and meets EU RoHS compliance.

IC695CMM002-DF IC695CMM004-DF



This change updated compliance markings on the packaging.

IC695CMM002-CF IC695CMM004-CF



This change addresses a component obsolescence issue. No change in functionality, performance or  compatibility.

IC695CMM002-BF IC695CMM004-BF



Label change only. No change in functionality, performance or compatibility.

IC695CMM002-AF IC695CMM004-AF





Adds  DNP3.0  Master  and  Slave  Unsolicited  Reporting  functionality. The release also adds the ability to configure the DNP3.0 Slave Analog Input Event Variation and fixes three issues in the DNP3.0 firmware

IC695CMM002-AE IC695CMM004-AE




See GFK-2461E for new features and problems resolved.

IC695CMM002-AD IC695CMM004-AD





Supports  Serial  Protocol  Language (SPL) scripting.

Corrects DNP3 Slave Bit Write issue. Please refer to M050803 - IC695CMM002_004 Product Safety Bulletin for more  information.

IC695CMM002-AC IC695CMM004-AC




Supports DNP3 Master and DNP3 Slave Protocol

IC695CMM002-AB IC695CMM004-AB




Supports CCM  Slave Protocol

IC695CMM002-AA IC695CMM004-AA



Initial Release

ST. LOUIS, Feb. 1, 2019 – Emerson today announced it has completed the purchase of Intelligent Platforms from General Electric.
All online orders placed before 4:30 PM EST “SHIPS SAME DAY FREE!" World’s largest warehouse of Factory Sealed GE 90-30 PLC, GENIUS I/O and RX7i PACSystem.highlight_off

PDF Electric & Supply Inc. sells new, new surplus and refurbished products which are sourced through independent channels. All warranties and support, if applicable, are with PDF Electric & Supply Inc. and not the manufacturer. PDF Electric & Supply Inc. is not an authorized distributor or representative for the listed manufacturers and makes no representations as to any quality control performed by any listed manufacturer on the products. The products listed on this website may vary as to their country of origin; the accessories, and other items included with the product; and the language used on the packaging, the parts, and any related instructions or printed material related to the products. This website is not sanctioned or approved by any manufacturer or tradename listed. Designated trademarks, brand names and brands appearing herein are the property of their respective owners.