problems with CP341

Hi,

I'm using a CP341 for serial communication to 4 boxes (temp measuerement).

The problem I had while testing was that the boxes fell of the bus, did not respond, these sort of thingS..., with a Scope I have seen signals of 1V and 2V, should be 5V, so replaced the modul with a new one, 500 euros cost...

Then I did some testing with a CP340, everything went good, 5V signals and all data good.

I received my brand new CP341, replaced the CP340 by this new one, guess what, signals of 2V ??????

The only thing that is different in the settings is the initial state of the receive line, in the CP340 I had to choose for 0 and 5V, in the CP341 I've selected None...,

I guess this modul is bad too ?

With a CP340, everything went fine...

You want to search the Siemens user forum
http://www.automation.siemens.com/US/forum/guests/PostShow.aspx?PostID=45153&45153&Language=en

Are you using RS485 or RS232 ?

485

485

Ps

PS:

I could set up the communication, but I measured signals of 2,5V, is this normal ???

Shouldn't be 5V ?

Combo said:

PS:

I could set up the communication, but I measured signals of 2,5V, is this normal ???

Shouldn't be 5V ?

Click to expand...

http://en.wikipedia.org/wiki/RS-485

Check out definition of RS 485