MODBUS on 1769-SM2

[GraemeTownsend]

Hi All.

I am trying to relocate a simple MODBUS system from a MicroLogix 1400 (on channel 0 set as a Modbus RTU Master) to an CompactLogix SM2 Module.

Image below shows set up of read and write to Node 1 of a simple RTU slave. As simple as it gets. Read some words from an address, Write some words to address.


I am struggling to find any documentation to do the same with the SM2. AB assure me it can be done but all the docs I find talk exclusively of talking to AB drives (in slave mode). Currently wading through the SM2 manual now.

Any advise welcomed!
Thanks.
Graeme.

 

[gclshortt]

https://www.youtube.com/watch?v=OvRD2UvrHjE

The above video is a good reference.
Even though the manual talks about the drives as slaves this is the exact same communication that you want. One master - Many slaves.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1769-um013_-en-p.pdf

Regards,