Despatch MIC1462 Controller Manual User Manual

Page 27

SECTION 3: OPERATION

3.1 Control Responses

Each instrument may be configured to provide three mode proportional control.
Proportional control is provided with Proportional Band, Integration, and Derivative
responses. The PID parameters are defined as follows:

Out 1 Out2

P (Proportional)

Proportional Band Pb1

Pb2

I (integration)

Automatic Reset

ArSt

D (Derivative)

Rate

rAtE

Manual Reset is provided for use in lieu of, or in conjunction with automatic reset. A
cycle time adjustment parameter is provided for use with each time proportioning
control output.

3.2 Direct/Reverse Operation of Outputs

Direct operation is typically used with cooling applications. On-Off direct output(s) will
turn on when the process variable exceeds setpoint. Proportional direct output(s) will
increase the percentage of output as the process value increases within the
proportional band.

Reverse operation is typically used with heating applications. On-Off reverse output(s)
will turn off when the process variable exceeds setpoint. Proportional reverse output(s)
will decrease the percentage of output as the process value increases within the
proportional band.

Output 2 will be Direct when Output 1 is selected as Reverse and Reverse
when Output 1 is selected as Direct.