IDEC MicroSmart Pentra - Manual (Page 100)

C ONFIGURING PID M ODULE USING W IND LDR
F C5A MicroSmart PID Module User’s Manual FC9Y-B1283 6-35
The fixed value control is a normal temperature control that the PID module controls the output to eliminate the
deviation between a single set point (SP) and the process variable (PV). The following diagram shows an
example of the fixed value control.
The program control allows you to define the set point (SP) that changes as the time progresses so that the
process variable (PV) can be controlled to match the set point (SP) changing as the time progresses. The set
point (SP) and time can be configured for each step. A maximum of 10 steps can be configured and performed.
The set point (SP) can be configured as shown in the following diagram.
(2) Control Register+53: Control Action
Selects either direct control action or reverse control action.
In direct control action, the output manipulated variable (MV) increases when the process variable (PV) is
higher than the set point (SP) (positive deviation). For example, freezers perform the direct control (cooling)
action.
In reverse control action, the output manipulated variable (MV) increases when the process variable (PV) is
lower than the set point (SP) (negative deviation). For example, electric furnaces perform the reverse control
(heating) action.
Step
Temperature
Set point (SP)
Time
Temperature
Time
Output Manipulated
Variable (MV)
High Low
Set Point (SP)
Process Variable (PV)
Output Manipulated
Variable (MV)
High Low
Set Point (SP)
Process Variable (PV)