Hello.

At collegue there are new Siemens Learning modules, more specific a PCS 7 DCS module with the PCS 7 v8,1 sp1 software for programming and  a S7 400 cpu 410 5h as a core, the cpu has its CP's (a 443-1 and a 443-5 ext). I've been trying to learn about it by doing the examples of the documentation in the web but I have a lot of questions and a I hope you can help me with them. (I have automation background, I know programming languages like ladder and scl, I've do some projects using PLC, etc. so please be as precise as you need).

1.- I download the demo library (the one in the topic title) and I want to know what limitations in compare with the licenced one will I have with this demo?

Thanks for your help

Regards

Wüstenräuber

Hi,

the demo version has no really limitation.
Without a license the Modbus block shows the status A090 (no error, only status), there are entries in the diagnostic buffer and the INTF/SF LED is blinking cyclically. But the communication works.

Wüstenräuber

 thanks for your kind answer friend.

1.- I have one doubt about it, when the INTF led begins to blink the PLC does not go to STOP mode?

Regards.

thanks man!!  

One more question please:

I've been searching in the manuals an it says that OB121 is about errors and has to be called in order to MODBUS comms to work, but where do I find this OB121? do I have to modify something on it to make it work? 

Regards

Wüstenräuber

Hi,

OB121 is an error OB. You must only create it and download to CPU. There are no changes needed, the OB must only exist.

Wüstenräuber

 Thanks for the advide friend. the problem was solved. at first when I compiled all the compiler erased OB121, in the log it said because no block or chart was using it, it will be downloaded, then I copy all the blocks and use the chart from the library examples and it worked!!! now I have communications running with the third party PLC.

Regards