camman
Member
I have 4 HSCE cards in an AB SLC 5/04 PLC. The counter cards are reading 0 to 10KHZ inputs from Micromotion flow meters and then the program totalizes the flow using the rate from the HSCE.
The problem is that the PLC scan cycles are so slow (due to the HSCE program rungs)that the PID blocks can't control the flow.
I have looked over the program and it looks like the HSCE cards are being initiallized every scan (multiple MOV blocks putting values into M0:6.0 ... M0:6.41 for each card, every scan cycle). The program then reads the values from the HSCE cards, (I:6.1, every scan).
My question is - Do all of these HSCE values need to be initiallized every scan? Reading the manual for the HSCE it looks like this only needs to be done once and then read the input every scan.
The problem is that the PLC scan cycles are so slow (due to the HSCE program rungs)that the PID blocks can't control the flow.
I have looked over the program and it looks like the HSCE cards are being initiallized every scan (multiple MOV blocks putting values into M0:6.0 ... M0:6.41 for each card, every scan cycle). The program then reads the values from the HSCE cards, (I:6.1, every scan).
My question is - Do all of these HSCE values need to be initiallized every scan? Reading the manual for the HSCE it looks like this only needs to be done once and then read the input every scan.