HELP on V350 PID loop - not working?

[murb]

I have a simple ladder with just a PID for a V350. I have setup some values manually. Shouldn't I see the PID control value change as I modify the PV? I understand that I need a hardware connection for autotune to work. I cannot hook this up to a critical piece of equipment until I know the PID will actually control. See the attached ladder.

[Emil]

In general,

- after setting some legal PID parameters,

- when you change PV somehow (connect potentiometer to the input, moving temperature sensor from glass with cold water/ice to galss with boiling water... or just linking temporary to MI, which is not linked ot hardware and then changing the value in this MI), or

- when you change setpoint;

You need ot see CV changing.

Please note - this test is -"go-no go" test. You can see if your program is proper at all, but you cannot tune the loop.

Very useful tool for debug, observe, log and tune PID loops is PID server. You can find it in VisiLogi or U90Ladder - in Tools menu.