Setting Profibus Node on a SIEMENS CP342-5

Hi,

I am replacing 2 Siemens S7 PLC's with a Control Logix Processor. I have decided to use 2 CP342-5 Profibus DP modules to replace the processors to allow me access to the old I/O on the siemens racks.

I can not for the life of me figure out how to set the node address on the CP342-5 so I can get access to the rack. I stupidly assumed that there would be a set of dip switches or dial to set the address.

My knowledge on Siemens PLC's is very limited

Can anyone please help me.

Thanks in advance!

I hope you havent purchased the CP342-5 modules.
To let the old S7-300 i/o stay as Profibus slave modules on the CLX master network, you would need IM151-1 modules (aka ET200M) to replace the S7 CPUs. On these modules the DP address is set via switches.

You can setup the S7 PLCs as slaves on the profibus network by means of the CP342-5 modules. You must then pass the physical i/o to the profibus i/o via the PLC program. All the setup is done in the HW config of the S7 program. It is a cludge but it will work.

Thanks Jesper,



Unfortunetly, Yes I have bought the CP342-5 modules and am trying to get them to work this weekend!!!

I was advised that these were the correct modules to use. I believed them because of my limited experience with Siemens and Profibus!

Am I correct in saying that you state that I can leave the CPU's in with an in-built DP connection and set them as a slave. Would this work?

I wonder if there is anywhere in the uk open tomorrow who could supply me with the correct modules I need. If not then I will have to cancel my installation.

This weekend is getting worse by the minute

Thanks for any other advice you could give me

SFBanks said:

Thanks Jesper,



Unfortunetly, Yes I have bought the CP342-5 modules and am trying to get them to work this weekend!!!

I was advised that these were the correct modules to use. I believed them because of my limited experience with Siemens and Profibus!

Am I correct in saying that you state that I can leave the CPU's in with an in-built DP connection and set them as a slave. Would this work?

I wonder if there is anywhere in the uk open tomorrow who could supply me with the correct modules I need. If not then I will have to cancel my installation.

This weekend is getting worse by the minute

Thanks for any other advice you could give me

Click to expand...

If you are going to use the S7 CPUs in as DP slaves, then you could just need logic in the S7s to Load and Transfer I/O image from the SST master.

Still kinda defeats the purpose of swapping out the S7 CPUs though. Maybe you could use that approach untill you get the proper IM modules.
Good luck

" I would rather be yelled at for being late, than yelled at for delivering s**t"


Ian

What can I say, other than "always confirm your planned setup with PLCs.net before purchasing anything".

Cheer up.
I would go straight to the aforementioned "expert" and ask him to sort out the matter. If I had goofed up like that on someone else's behalf I would go overboard to try and rectify the situation.
I hope you explained what you wanted to achieve to him clearly enough to begin with. As far as I understand you want to eliminate the S7 CPUs and retain the i/o. All code shall then run on the CLX CPU.

If you still want to use the CP342-5 modules as suggested before, I can try to dig up some guides. But be warned that it can be a bit tough for a beginner with S7.

edit: By the way, I dont have the pricelists right here, but the IM modules are a lot less expensive than the CP's.

Thanks guys!

Gonna cancel my installation! need to put everything back the way it was.

I will be straight on the phone first thing on Monday to get the correct cards ordered and give them a piece of myt mind

At least I will get some of my weekend back.