Convert Modbus to CIP help

[BillRobinson]

Need a little help here,

I need to poll a radio/modem over Allen-Bradley Ehernet/IP. The existing radio/modem is geared up Modbus. Anybody know of some device that can convert Modbus to CIP? I know I can put a Modbus card in the control-logix chassis but I rather not do that because of space in the rack. Is there a way i can poll through the Ethernet card?

 

[Eddie Willers]

Tell us more about the "radio/modem". Is this an "Ethernet Radio Modem" or is it a serial modem with a Modbus RTU serial device connected on the other end ?

The Digi One IAP is the best device I've found for translation between A-B Ethernet protocols and Modbus RTU.

 

[puravdagli]

Assuming that the radio modem talks Modbus RTU I would suggest a solution that I have used widely and absolutely love. It is the wonderful little Micrologix 1100. I can write pages on the advantages of using the MLogix 1100 for ModbusRTU - EthI/P conversion, but I will mention below a few points just to get you a brief idea.

- MLogix 1100 has a built in COM port which when used with 1763-NC01 cable talks Modbus RTU Master or Slave without any problems.
- MLogix 1100 has a built in Ethernet I/P port which can be used for peer-to-peer communication with any other AB PLC.
- Using an RSLinx ethernet driver, an OPC topic can be created that serves out the entire data table of the MLogix 1100 over OPC for use in supervisory software.
- Apart from the communications capabilities, the MLogix 1100 has available on board analog and digital I/O in various configurations.
- The MLogix 1100 also has a little LCD display that can greatly help in troubleshooting.

The list goes on...

I have some standard example programs that demonstrate Modbus - EthI/P conversion using the MLogix 1100. Let me know if you are interested...

 

[puravdagli]

I have tried using the DigiONE IAP for the same solution but have come across some serious issues with its speed and reliability. I do not trust it at all.