RSLx5000 PID limit flags

DairyBoy

Member
Join Date
Jun 2007
Location
UK
Posts
393
Hi All. Yes, I know I'm just adding to the vast bulk of pid questions but searching through them was becoming a pain.

Quote from the help file:

You can set an output limit (percentage of output) on the control output. When the instruction detects that the output has reached a limit, it sets an alarm bit and prevents the output from exceeding either the lower or upper limit.

So: Are they referring to .MINO & .MAXO and the associated alarm bits .OLL & .OLH?

Thanks.
 
yes ...

but just be careful with how you plan to use those "alarm bits" ...

specifically, when I just tested this out in my lab, putting the PID into the "Software Manual" mode would only let me manually set the CV within the limits defined by MAXO and MINO – but when I bumped against EITHER limit, the "alarm bits" did NOT get set to a status of ONE ...

so ...

make sure that your operator can't defeat any intended "alarm" action by manually cranking the CV up or down ...

when the PID was NOT in manual operation, then the bits acted the way that (I think) you're expecting them to ...

as always – test and confirm ... one size does NOT fit all ...
 
Last edited:

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