Hi...

No one has the solution for this?

Still i didn't get reply....

At this point the length of the received data block is displayed in the parameter LEN.
(Extracted from the manual Loadable Driver....Modbus RTUMaster).
You can wait for the acknowledge of reception by the NDR output to trigger the Send FC for the second slave, and wait for the NDR from the 2nd slave's Recieve FC to trigger the first slave's send.... Noticew you will also need a startup trigger to start the cyclic call of slaves. You will also have tomonitor the status of the Send and Recieve FCs so you don''t get stuck in the program because the NDR does not come up.

Another way I have used when repies are steady is to use a timer/counter combination to generate separate cycliucally triggers to each Send FC. But that is more touchy: itrequires extensive testing of all slave's comms, and undersdtanding of each s;ave's comm. delays so you are sure you will not trigger one while the other is operating.

In any cse, please study the example programs provided in the Modbus master manual, they really are the basis of any development for a Siemens Modbus RTUmaster
Hope this helps,
Daniel Chartier