GE Series 90-30 PIDs

[NetNathan]

This may also help.
There are some highlighted sections that explain sort of what you want to do.

 

[Bit_Bucket_07]

One possibility would be change the upper and lower clamps and the slew rate when you put the loop into manual. Upper Clamp is located at the starting address plus 9, lower clamp is starting address plus 10 and minimum slew time is at starting address plus 11.

So, what I wound up doing is leaving the PIDs unconditionally enabled and switching from manual to auto mode instead. I did move the manual speed/position entries into Ref+13 when in manual mode and that gives me the bumpless transfer that I was seeking. I didn't bother to change the clamps or slew rates, and instead, simply moved the operator's manual entries, rather than the PID CV values directly to the analog outputs when in manual mode. That allows the operator to have complete control of the CV when in manual mode.

 

[Steve Bailey]

Plenty of ways to skin that cat. Glad you got it working.

 

[Bit_Bucket_07]

Plenty of ways to skin that cat. Glad you got it working.

I can understand how some might prefer to have the clamps and slew rate applied to manual control, but my client didn't want that. So, I learned some more about the 90-30 PID controller. That was interesting.