Hello forum participants,
I guess the title says it all but here
once more.

What is meant by statement "channel is forced"?
How is the enforcement actually done?

Yours sincerely
Ariel Burbaickij

 

You did not provide much information but I think that the "forcing" you are refering to is a term used with control systems to indicated that the value (discrete or variable) of a channel (input or output) is being written by the system software rather than the actual or computed value. This action is also called "disabled" or "override". For example, you want a discrete output ON to test. The PLC or DCS logic has it OFF. You then force the output ON and it will be ON regardless of what the application program determines. Some systems only permit forcing of discretes, some can also force analog (variables).

Caution: If a channel is forced ON or OFF, check to ensure that the removal of the force does not leave the channel in an unsafe condition.

 

Dear Friend,

I suppose your question is about a display message from any control equipment.

One channel may be in general analog in or out, and its normal state is in "active" is est, measuring the analog input or sending the analog output, but when you want <or the system control)to put any value in this channel that don´t is the field value or the proportional result from the control (output) the channel can put in forced, for example, if the field value in your input is in any instant 14 mA, but you want to forced to 4mA.