s7-1200 mms440 on uss

Hi there im trying to put 4 x 440 drives connected on uss to a s7-1200 (first time).I cant seem to get any communication between the plc and the drives.I am using a cb1241 rs485 comms module and have the wiring connected as follows taq and t/ra linked together and then out to the drives as well as tb and trb linked together and out to the drives, i have a resistor across them at the comms module and also a resistor on the last drive with the extra legs of the resistor card connected to 0v and 10v, i also have all the drives 0v connected back to the m on the board.
The mms440 parameters i have set are as follows
700-5
719-55
1000-5
2010-6
2011- 1 to 4
i may have done/missed something simple in the program but i cant see the woods for the trees sort of thing, any help would be greatly appreciated
Alex
ps i tried to attach the program but its too large, the software version is v11

Did you check the Siemens support / application web pages?
They have a number of examples that are pretty close to what you want to do:
http://support.automation.siemens.com/WW/view/en/40157517
http://support.automation.siemens.com/WW/view/en/37604154

They are for a G110, but that should not matter.

Hi!
I did the same recently, but using Step7V54 and a Vipa 315. I used a 485/232 converter and hyperterminal (or was it YAT?...ah, never mind) on the PC to listen to the link to see if the master sent as expected and the slave responded. It is allways fuzz with character lengths, baud rates, telegram lenghts and shifting A-B half a dozen times.

I would have started the testing with the 1200 and only one MM4.

Do you btw have the description of the USS telegram?

EDIT: Eureka! https://a248.e.akamai.net/cache.aut...5734889_FAQ/Using USS protocol with MM420.pdf

Kalle