IDEC MicroSmart Pentra - Manual (Page 104)

C ONFIGURING PID M ODULE USING W IND LDR
F C5A MicroSmart PID Module User’s Manual FC9Y-B1283 6-39
(17) Control Register+35: Loop Break Alarm Time
Configure the loop break alarm time to detect the loop break alarm. The loop break alarm is disabled when the
loop break alarm time is 0. When one of the following conditions is met, the PID module considers that heater
burnout, sensor burnout, or actuator trouble is detected and triggers the loop break alarm.
When the reverse control action is selected:
• The loop break alarm is triggered when the process variable (PV) does not rise as much as the loop break
alarm span within the loop break alarm time while the output manipulated variable (MV) is 100% or the output
manipulated variable upper limit.
• The loop break alarm is also triggered when the process variable (PV) does not fall as much as the loop break
alarm span within the loop break alarm time while the output manipulated variable (MV) is 0% or the output
manipulated variable lower limit.
When the direct control action is selected:
• The loop break alarm is triggered when the process variable (PV) does not fall as much as the loop break
alarm span within the loop break alarm time while the output manipulated variable (MV) is 100% or the output
manipulated variable upper limit.
• The loop break alarm is also triggered when the process variable (PV) does not rise as much as the loop
break alarm span within the loop break alarm time while the output manipulated variable (MV) is 0% or the
output manipulated variable lower limit value.
Even when the loop break alarm is triggered, the PID module continues its control. To stop the control, ladder
programming is needed.
Ladder Program Example
The control register is D1000 in this example.
(18) Control Register+36: Loop Break Alarm Span
Configure the loop break alarm span to detect the loop break alarm. The loop break alarm is disabled when the
loop break alarm span is 0.
(19) Control Register+95: Cooling Method
When the heating/cooling control is enabled, select the cooling method from air cooling, oil cooling, or water
cooling. The output characteristics for the cooling output manipulated variable (MV) are shown below.
Air cooling: linear characteristic
Oil cooling: 1.5th power of the linear characteristic
Water cooling: 2nd power of the linear characteristic
Output Characteristics of Cooling Method
Process Variable (PV)
△
Set Point (SP)
100%
0%
Water Cooling
Oil Cooling Air Cooling
Manipulated
Variable (MV) Cooling proportional band
When external input I0 is turned on, CH0 control is enabled. When
Q0 (loop break alarm output of CH0 control) is turned on, CH0
control is disabled.
When loop break alarm is triggered, D1010.2 (loop break alarm
output) is turned on, and Q0 is turned on.