Powerflex 40 start and stop with msg instruction.

Hello everyone,
I am having some troubles with getting a powerflex 40 to run from a msg instruction thru a Ethernet connection from a micrologix 1100 and ethernet switch 1783-US05T . I am using a timer instruction that initiates all of message intstructions when PLC is turned on.
I have the timeout msg N42.3 set to 5 sec. I have the write logic msg set to N41:0 and I am using a mov instructions triggered by four separate inputs that are set for the stop,start,forward and clear fault functions to the drive. I have the speed reference write and read msg set to N41:2 along with a scaling instruction for the speed of the drive.

Is there something I am missing?

I very strongly discourage the use of this method.

That being said, if you can ZIP and post your program, somebody can take a look at it. From the logic description, it's impossible to guess what your logic does wrong.

Do any of the MSG instructions ever fail ?

Remember that the output MSG has to execute more often than the command timeout value.

If the command timeout has not been written to the drive yet, the output MSG will be rejected by the drive (an /ER, not just a timeout).

Ken I wouldn't use this method either but I have equipment at work that are programmed this way and I just wanted to get a better understanding of it.

I agree with Ken !

If the last instruction to the drive is run and then the cable is cut, what will tell the vfd to stop then?

james