Mitsubishi Q4AR Partial Differential PID instructions

Hi List,

We use Mitsubishi Q4AR Redundant PLC in a chemical plant. The common PID instructions (So-called Complete Differential PID instructions) worked OK in single CPU system but not OK in redundant dual cpu system in CPU switching. (Fatal Error occurs) Taiwan Mitsubishi distributor told us to use another PID instruction set (Partial Differential PID instructions) and send us a simple manual.

Some parameters are not in detail.

We can run a simple loop with unpredicted result but I even failed to turn the control loop into auto mode if we have more than one loop.

Anyone here once used Mitsubishi Q4AR Partial Differential PID instructions. I would like to ask you about something in detail. Please e-mail me directly.

Thanks in advance.

Frederic Chui, Everdation Technologies
[email protected]