Hello, 

I faced with a communication error when I using USS protocol to run 4 drives, 

im using S7-1212 with V20, using signal board CB 1241 (RS485) 6ES7 241-1CH30-1XB0

In the past I ran several applications using the same method of USS, I followed the recommended 

instructions by Siemens and never had any issues 

Im using the instructions from "Communication processor" > USS > USS_PORT and USS_DRV

followed exactly the Siemens  recommendations, I located the USS_PORT in the cyclic instruction 

and for each drive I'm using the same "USS_DRV_DB" , Im only changing the drive number . Nothing unusual 

all the drives are configured for the USS

I also ran the program on PLSIM, everything was clear without any errors. 

Please help with that issue 

Are your RS485 USS network connections properly terminated on each end?

Vadimcougar

Hello, 

I faced with a communication error when I using USS protocol to run 4 drives, 

im using S7-1212 with V20, using signal board CB 1241 (RS485) 6ES7 241-1CH30-1XB0

In the past I ran several applications using the same method of USS, I followed the recommended 

instructions by Siemens and never had any issues 

Im using the instructions from "Communication processor" > USS > USS_PORT and USS_DRV

followed exactly the Siemens  recommendations, I located the USS_PORT in the cyclic instruction 

and for each drive I'm using the same "USS_DRV_DB" , Im only changing the drive number . Nothing unusual 

all the drives are configured for the USS

I also ran the program on PLSIM, everything was clear without any errors. 

Please help with that issue 

Hello 0_Einstein, 

Yes the wiring connection is correct, even added original termination resistor on the end of the network (the last VFD) 

still got error 

I highlighted the topic title, right-clicked and searched online for that.

One of the returned links may prove helpful.  Maybe this one:

https://support.industry.siemens.com/forum/WW/en/posts/818b-invalid-pointer-to-the-local-data-source-destination-size-not-correct/204432

Vadimcougar

Hello 0_Einstein, 

Yes the wiring connection is correct, even added original termination resistor on the end of the network (the last VFD) 

still got error 

Thanks 0_Einstein,

Case is closed, I found that the CB 1241 is faulty, I replaced with a new one and it works right away

:)) 

thank you for your support  

I am having the same problem, can you help me?

Have you followed the prior steps?  Did you also replace your CB-1241?

anh_tuan2003

I am having the same problem, can you help me?