Hi,

I was reviewing the logic for feedwaters pumps speed control,
downstream PID for speed regulation, there is a MA_EXT bloc, that allow operator to control manualy the speed % if needed.

Something seems strange:
this bloc has no tracking command input, and no tracking setpoint input
but his tracking output is true

I wonder how it's possible ?

 

Hi,

I was reviewing the logic for feedwaters pumps speed control,
downstream PID for speed regulation, there is a MA_EXT bloc, that allow operator to control manualy the speed % if needed.

Something seems strange:
this bloc has no tracking command input, and no tracking setpoint input
but his tracking output is true

I wonder how it's possible ?

Did you find an help definition of the mentionned block?

 

Did you find an help definition of the mentionned block?

yes, i've read it and it states: "if tack command input is true then track output is true"

also if your question is about "unexpanded" bloc, it's not, it's a regular MA_EXT

 

What stand for MA..?..

Can you describe more on feed water pumps speed regulation..

It would be nice to have a picture of what is done in application code..

 

Looks like that MarkVIe is used as DCS or BOP controller ...I do not have app code for these case

 

MA means Manual - Auto

TK_OUT is used (and trust me) is true
but there is no CMD_TK nor TK setpoint

 

I see a "CMD " at the top right of the block what is used for ? CVO CV SP?

 

it's the command output:

CVO is command variable output
CV is command variable
SP is setpoint

difference between CV and CVO is like CVO is raw output, als CV can be filtered
for example, you can add correction curve to CV
SP is used if the bloc is needed to generate a dynamic setpoint for an another regulation