communication between different PLCs
communication between different PLCs
(OP)
I have one AB compactLogix PLC and one GE 90-30 PLC (client prefered), if I choose DH+ to communicate between these two, do I need to have any converter for the GE PLC or just plug these two and they can talk to each other? I am new in this field, please help. Or should I insist to have AB series PLC instead of GE (have to have long long talk to client for this).
Thanks,
Thanks,





RE: communication between different PLCs
Chris Elston
Automation & Controls Engineer
http://www.mrplc.com
Download Sample PLC Ladder Logic Code
at MrPLC.com
RE: communication between different PLCs
RE: communication between different PLCs
One thing I forgot...SST makes a card that drops into a GE 90-70 rack. You didn't say which GE model you have.
If you have a GE 90-70, then SST has what you need.
http://www.mysst.com/cards/ab/sdvme.asp
http://www.mysst.com/bcm/content.asp
Chris Elston
Automation & Controls Engineer
http://www.mrplc.com
Download Sample PLC Ladder Logic Code
at MrPLC.com
RE: communication between different PLCs
Hmmm, I know that it is yesterdays technique, but pulling a number of discrete + analog signals between the two can be the easiest and cheapest way to do it.
Off course, its not so flexible, but if you arrange for a number of spare signals then it cant go completely wrong.
Dont use OPC for realtime data transfer. There will be significant timedelays (0.5 secs cycle time is not unheard of).
AB supports Modbus out of its serial port. Dont know about GE.
Probably DeviceNet is the most native to the CompactLogix, but I am not sure if it is as easy as one thinks to make the connection between an AB and a GE.
It is certainly possible, I just thought that I ought to mention the arcaic way of doing it. ;)
RE: communication between different PLCs
RE: communication between different PLCs
RE: communication between different PLCs
RE: communication between different PLCs
GE does support Modbus. You can roll your own in a processor card or buy the Horner one which has the code already in it. Much easier.
Be prepared to write a lot of ladder to get the communications going. I found some samples on the GE-Fanuc website.
RE: communication between different PLCs
Don't SHOOT, however I have to asked. Since your client is GE is the AB system small enough to convert it to GE. At first thought it may sound bad, however there may be merit to do this. I did 2 GE Devicenet systems then my client had me convert the GE to AB. In retrospect I wished I would have converted the first two. Just food for thought.
RE: communication between different PLCs
RE: communication between different PLCs
With the Devicenet module both PLCs can run their own logic. You can map I/O tables and registers directly to each other. Example a word of Q outputs would be mapped to the Input image table in the AB.The same would be true for data registers. The delay would be Scan time plus Devicenet Communication time.
RE: communication between different PLCs
I need What steps I could take in account ? for to fix or trobleshooting in field.
thanks
RE: communication between different PLCs
'automation99' - It's not going to be cheap any way you do it. DeviceNet or Modbus will work, but it is going to require more hardware for at least one or both to achieve it.
DeviceNet = Scanner module for Controllogix + Horner's DeviceNet slave for GE. (don't forget the expensive cable, resistors, power supply for the network and $2000+ for RSNetworx)
Modbus = Prosoft Modbus Master for Controllogix (I believe the 90-30 should support ModbusRTU, depending on the CPU you have). You will have to read-up on Modbus if you are not familiar w/ the protocol. It's going to take more than 30 minutes to do this either way you look at it.
'Wfacac' - MAN ... I wish it was that easy! So far in the industrial world of PLCs everyone's Ethernet protocols are proprietary just like the old serial protocols. (Just because your telephone will plug into the PLC doesn't mean you can call it.