COmpact Logix & FOXBORO DCS

Hi Every body
I am using compact logix L31 processor and MVI-MCM prosoft module to communicate over Modbus network with FOXBORO DCS (I/A Series version 8). My Compact Logix/MCM module is acting as a slave and DCS is acting as a master. Here is the story:

we seemed to have some mapping issue at the MCM (SLAVE) and FOXBORO DCS system as a Master. Where would a mapping be done, in slave or in Master? I mean to say, for example, in my Compact Logix panel which is acting as a slave , master wants to read an analog point over Modbus network. Since FOXBORO DCS (MASTER) is on Modbus, it sends a command say 40001 to read an analog point in the slave. How would we map that analog point with modbus registers (like function code 4 (30001...), or 3 (40001.....))? Where would that mapping needs to be done either in Master or slave end.

It makes sense to me these data points have to be mapped before master start sending commands to our slave. Also master just wants to read some analog and digital points, no write involved. How do we map these data points, and where (i mean would the mapping thing be the part of master end or at the Slave end).

I have also put up the same concern to Prosoft guys, but they havent replied to me, and i am right now at the site so any help from you guys will be appreciated. Thanks in advance
Regards

What is the master in the DCS? FBM224 or a Modbus integrator 30? Since your I/A is version 8, I assume your AW is windows based and not Solaris. Have you looked into using ethernet and PLC-5 reads/writes instead?

Anyway:
I would do all mapping in the slave, to one big memory block, then the master can get all data with one poll, should help speed up communication.

Warning: I've done Modbus, but not on either system you're working with, so my comments are somewhat generic.

If I read the section on the Prosoft's Module architecture correctly, it seems that the Prosoft module maintains its own internal database (illustrated on page 17, MVI56_MCM pdf Prosoft manual), presumably of the tags configured for it.

On page 40, the screen shot of a configuration page indicates that you establish which CLX registers are going to be read, by CLX tag name.

Hence, I suspect that the reads from the master will read the CLX tags in the consecutive order established by the internal database in the Prosoft.

The map of the CLX slave then, is probably the order in which you configure tags in the Prosoft internal database. Prosoft seems to manage the overhead of maintaining that database with the CLX processor.

It appears that Ken's suggestion for one big memory block is accomplished by configuration of the Prosoft module's internal database.

Dan

Hi
The master in dcs is FBM 231, 4 ports serial and it is windows version. How can i do the mapping in Slave, i mean if you can give me an example it will be easier for me to go by. For example if DCS on modbus wants to read a tag from my compact logix, say AI[0].SCALED, how would i map it interms of modbus reguster 40001

Thanks

I've used Prosoft modules with SLCs. The Prosoft unit I've used comes with setup software that lets you identify registers in the SLC to read and the Modbus registers in the module that the data is mapped to. You don't need to do any ladder logic.

There are lot's of Prosoft modules available. What model are you using?

I am using MVI69-MCM Module......

plcnovel said:

I am using MVI69-MCM Module......

Click to expand...

Pls help me out in this, i am sitting right at the plant and seemed lost too.....

Thanks

I suggest you download and read the module manual, you can get it here:
http://www.prosoft-technology.com/content/view/full/5915
the configuration file is available also.

I've used the prosoft modules with PLC-5's, but never the Compact Logix line.
I took a look at the manual, and this module operates pretty much like all the others. You move data from the processor to the specified module addresses, the manual has a lot of examples, and is very extensive.

You should be able to move any PLC registers to any properly configured Module memory address.

Are you sure you have the FBM231 configured correctly, the 231 supports multiple protocols and communication standards.

Are you the PLC programmer or the DCS guy? or both.

Ken Moore said:

I suggest you download and read the module manual, you can get it here:
http://www.prosoft-technology.com/content/view/full/5915
the configuration file is available also.

I've used the prosoft modules with PLC-5's, but never the Compact Logix line.
I took a look at the manual, and this module operates pretty much like all the others. You move data from the processor to the specified module addresses, the manual has a lot of examples, and is very extensive.

You should be able to move any PLC registers to any properly configured Module memory address.

Are you sure you have the FBM231 configured correctly, the 231 supports multiple protocols and communication standards.

Are you the PLC programmer or the DCS guy? or both.

Click to expand...

Hi Ken
Thanks for your advice. I am the PLC programmer and i have no idea whats going on at the DCS end. All i know, the dcs guy is sending a query with say address 40001 and he wants to read my compact logix tag AI[0].SCALED. but i dont see any mapping in my ladder logic. One more thing, i didnt write the ladder at the first place. I am just here to commission this unit. But i dont see any data mapping in my plc ladder.
So you said that data can be easily moved to a properly configured module memory address. In this example, i guess i have to first copy my tag AI[0].SCALED to internal memory address and then i have to map that internal memory address with a modbus register 40001.....is it correct? If you can just give me an example of how it can be done it will be a lot easier for me to do the rest...i would really appreciate your favor. Thanks in advance

Rtfm!!!!!
There are many, many examples.

Ken Moore said:

Rtfm!!!!!

Click to expand...

Whats rtfm ?

Read the F***ing manual

Ken Moore said:

Read the F***ing manual

Click to expand...

Thats a new one on me, but i like it