PROMOTIC FORUM

Hi,
i need to do the byte swap of variable, what i get from Siemens PLC.
with 2 variable its work:
pMe.Pm("/Data/#vars/v1").Value = Pm.TransformValue(pMe.Pm("/Data/#vars/v1_raw").Value, 1)

i don't understand - how it must work with 1 variable, same variable what i read from PLC to PmaData with comm.data extension?

If you want to read a 2-byte variable from a Simatic PLC (I assume using the PmS7 driver)
and as a result you want to have a swapped value (12->21) in the variable in the PmaData object,
then the best is:
do not use the data extension,
place the variable in the PmaCommGroup
and in the onDataReceive event convert the value of this variable using Pm.TransformValue(v,1)
and assign it to the variable in PmaData without using the data extension.

Petr Návrat
navrat@microsys.cz