S7 communicating to Allen-Bradley Logixs


I have an application where by, I need to communicate to an
allen-bradley control logixs processor from a seimens s7 plc.
Has anyone done this with success? and how do you do it?
Reply to
Mamilovic
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How much data do you need to transfer? How fast? Options are: Profibus, limited number of registers but you can multiplex them.
Hardwire, really limited but could be all you need for two or three signals.
Serial, use Modbus to transfer an almost unlimited number of registers. I think the S7 serial module also supports some of the more basic AB serial protocols.
Multiplexed hardwire link, say 16 bits of data and maybe 8 bits to multiplex.
If you are braver still, try connecting them together over Ethernet...
Cheers Steve
Reply to
SteveO
Tell me more about the serial Modbus and Profibus option? Hardware required? Thanks John
SteveO wrote:
Reply to
Mamilovic
John,
Hardware required: two modules, one CP in the S7 rack and one Prolinx module in the logix rack. The S7 CP will need some special Modbus software and licenses. The S7 Modbus software needs to be ordered as Master or Slave and you get a tiny blue dongle that plugs into the CP that I suppose indicates you paid for it. The S7 is programmed using functions that will read or write quite a bit of data, up to the Modbus limit per packet (128 words I think). Add more function calls to get more packets. It was easier than I anticipated, Siemens have really got their act together with the S7 - you even have access to FAQs and How- To's. Crikey!
The logix side I am not so sure about - check out the Prolinx site.
formatting link
will take you straight there. The S7 module needs to be ordered to be RS232 or RS485 or (shudder)20mA loop. If the logix prolinx is like the stand-alone prolinx converters then the module should support both RS232 and RS485.
This sounds like a very interesting project. I wish you many hours of fun.
Cheers Steve
Reply to
SteveO
I would use Profibus DP due to higher transfer rates. The multiplexing, mentioned above, is easy. S7-3xx have Profibus DP built in. The ControlLogix requires a Profibus DP card. Search for ControlLogix Profibus DP and you will find many links.
Reply to
Peter Nachtwey
Finished a job not to long ago where Siemens S7, AB ControlLogix, and DeltaV had to communicate. We used Profibus DP.
Both DeltaV and S7 required they were the master. So all three systems were set up as masters, and we used DP/DP couplers to allow them to communicate. This is a simple device that allows multiple masters to talk to each other by acting as a slave on both ends. Sorta like an OPC mirror application, but it was a nice, simple hardware box.
Commincations were fast and flawless.
Nathan
Peter Nachtwey wrote:
Reply to
nc_043

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