OMX rs232 control interface and compact logix plc

I have an OMX RS 232 control interface unit which needs to be interfaced to Compact logix plc using rs232 communication protocol. I need to read the values into PLC from field using the OMX interface unit. values like temperature and RH are to be read.Once i pass some message instruction/string into OMX unit it should be able to read that and give me back the information from field. But the dont know whether the the information which we get back into PLC is a message instuction or a string..!!

Am attaching a copy of OMX unit.Kindly let me know how can do this interface ? what should i set in the PLC and how do i read the values from field.?

pls help me out..

Well... That brochure helps not at all. No protocol, no encoding, no command information.

But, it doesn't use MSG instructions, I'll tell you that much.

Use the ASCII read and write instructions, and PARSE the return string manually.

Strangely, there are even (basic) examples in the "Instruction Help" part of RSLogix 5000 software under 'ARL', 'ACB', 'AWT', well, ALL of the Serial Port Read/write instructions.

Thnx 4 ur reply...but if it doesn't support mesg instruction then what kind of characters does it supports?