Step7 and Modbus problem

I have to program a communication between a Siemens S7-300 with CP341 and a Slave Modbus from other manufacturer (Sofrel). Anybody know the way to do that?. Anybody have an example or the driver for Hardware Configuration of CP341 Master?
Thank you

Do you want to set up an ethernet connection between the modus gateway and the CP341?

CP-341 MB Master

I have code for MB Master driver (fcn 2, 3, 16) that I modified from Siemens tech support guru M. (mike/mark/mack?) McCay's demo code. It has a polling routine along with MB Host Read/Write function blocks. Since I don't write via MB I can't say how that part works, but the read function is good.

Did you know that Siemens sells Modbus personality modules that plug into the CP's?

Hello;
The following link will take you to the Siemens support webpage that allows you to download a modbus driver (master or slave) for the serial CPs of the S7-300/400; you will also find programming manuals for the implementation of Modbus function calls; you can basically copy the functions< blocks in your program and modify them to suit your needs.
For this to work, you will need to buy a Modbus driver licence from Sieemns (it actually consists of a hardware dongle you install in thje CP341, so it can't be copied); you will also need to install the P-to-P CP parameters software (downloadable fron<m the same site, also comes with the Modbus dongle).
Hope this helps,
Daniel Chartier

TJ, You must be talking about Murry MacKay. I think he wrote the Modbus driver for the S7-200 PLC.

Dear Daniel,
you can please indicate the link to the siemens support webpage you refer below?

Thank you very much
Gilberto Vitor

dchartier said:

Hello;
The following link will take you to the Siemens support webpage that allows you to download a modbus driver (master or slave) for the serial CPs of the S7-300/400; you will also find programming manuals for the implementation of Modbus function calls; you can basically copy the functions< blocks in your program and modify them to suit your needs.
For this to work, you will need to buy a Modbus driver licence from Sieemns (it actually consists of a hardware dongle you install in thje CP341, so it can't be copied); you will also need to install the P-to-P CP parameters software (downloadable fron<m the same site, also comes with the Modbus dongle).
Hope this helps,
Daniel Chartier

Click to expand...

Yes, I´d found it.

http://www4.ad.siemens.de/WW/llisap...view=4000003&viewLevel=6&wttree=cs&jumpto=260

Thanks.

gilberto_viconsult said:

Dear Daniel,
you can please indicate the link to the siemens support webpage you refer below?

Thank you very much
Gilberto Vitor

Click to expand...

modbus driver

You must go to this page

http://www4.ad.siemens.de/

and open the tree in this way: Automation Systems>Simatic>PLC>S7-300>communications>Loadable Drivers for CP441 and CP341...

you can download it from here.

If you have the Software "CP PtP Param", obtained if you bought some S7-300 communication processor, you´ll can use this Modbus drivers and write your program with the blocks P_RCV_RK (FB7) and P_snd_rk (FB8).

Sorry for my english

Good Luck