IDEC MICROSmart FC6A Series Ladder Programming Manual page 397

6. Sampling Period (S1+5)
Set the cycle to execute the PID control.
PID control will only be executed at the end of the scan.
When the sampling period is set lower than the scan time, PID control is not executed with the set sampling period, it will be
executed with the same period as the scan time.
When the sampling period is set longer than the scan time, if the scan has not finished when the sampling period has elapsed,
PID control will wait until the scan ends and then be executed.
Due to the above factors, an error will occur between the sampling period and the actual PID control execution timing.
The sampling period can be set from 0.01 to 100.00 seconds in 0.01 second increments.
Sampling period ≤ Scan time
PIDA instruction executed
Scan time
(60 ms)
Sampling period
(40 ms)
PID control executed
Sampling period > Scan time
PIDA instruction executed PIDA instruction executed PIDA instruction executed PIDA instruction executed PIDA instruction executed
Scan time
(60 ms)
Sampling period
(40 ms)
PID control executed
7. Advanced/Basic
Click this button to show or hide the advanced settings.
On the Input tab, Sampling Period (6) can be set as an advanced setting.
8. Alarm 1 (Process High Alarm) (S1+3)
Set the upper limit value of the process variable (1).
The alarm 1 value can be set in the range between the alarm 2 value (process low alarm) (9) and the maximum value (4).
If the process variable is higher than or equal to the alarm 1 value, the alarm 1 output (S3+3) turns on.
If the process variable is lower than the alarm 1 value, the alarm 1 output (S3+3) turns off.
9. Alarm 2 (Process Low Alarm) (S1+4)
Set the lower limit value of the process variable (1).
The alarm 2 value can be set in the range between the minimum value (5) and the alarm 1 value (process high alarm) (8).
If the process variable is lower than or equal to the alarm 2 value, the alarm 2 output (S3+4) turns on.
If the process variable is higher than the alarm 2 value, the alarm 2 output (S3+4) turns off.
A maximum of four alarms (Alarm 3 to Alarm 6) can be configured for the process variable in PID control.
Individually configure Alarm Type (10), Alarm Value (11), Hysteresis (12), and Delay Time (13).
PIDA instruction executed
0 ms 60 ms
0 ms 80 ms
PID control executed
0 ms 60 ms
0 ms 80 ms
FC6A S MICROS
ERIES MART
PIDA instruction executed PIDA instruction executed
120 ms
160 ms 160 ms 160 ms
PID control executed PID control executed
120 ms
160 ms 160 ms 160 ms
PID control executed PID control executed
L P M
ADDER ROGRAMMING ANUAL
19: PID C
ONTROL
PIDA instruction executed
180 ms 240 ms
240 ms
PID control executed
180 ms 240 ms
240 ms
PID control executed
FC9Y-B1726
I
NSTRUCTION
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