IDEC MICROSmart FC6A Series Ladder Programming Manual page 406

19: PID C I
ONTROL NSTRUCTION
This function is suitable for the control of high-temperature heaters (elements composed of molybdenum, tungsten, platinum,
used at approximately 1,500 to 1,800°C) that burn out when rapidly energized.
11. Proportional Band Offset (S1+20)
Sets the offset for the proportional band. The output manipulated variable (S1+1) can be increased or decreased by the value
set as the proportional band offset.
For example, if the proportional band offset is set to 20%, the output manipulated variable (S1+1) is increased by 20%.
The proportional band offset can be set from -100 to 100%.
12. Control Period (S1+21)
Set the cycle to perform on/off control of the control (S3+5) output according to the output manipulated variable. The on pulse
width for the control period varies according to the output manipulated variable.
The control period can be set from 0.1 to 50.0 seconds in 0.1 second increments.
When control period: 5 seconds (set value 50)
OFF
Control output
13. Advanced/Basic
Click this button and you can show or hide the advanced settings. On the Output tab, Output Manipulated Variable Limit (6),
Output Manipulated Variable Upper Limit/Percentage (7), Output Manipulated Variable Lower Limit (8), Manual Mode Output MV
(9), Output MV Rate-of-Change (10), Proportional Band Offset (11), and Control Period (12) can be set as advanced settings.
S1: Control Registers
Storage
Destination
S1+0 Process variable
S1+1 Output manipulated variable
S1+2 Operation status
S1+3 Alarm 1 (process high alarm)
S1+4 Alarm 2 (process low alarm)
S1+5 Sampling period
S1+6 Control mode
S1+7 Set point
S1+8 Proportional band
19-16
Output manipulated
variable (80%)
ON (4 s) OFF
5 s
Function
• When Analog Input is specified
AI0 to AI5 can be selected. S1+0 is read-only.
• When Data Register is specified
Store a value that satisfies process variable minimum value ≤ process
variable ≤ process variable maximum value. S1+0 is readable/writable.
Store a value between 0 and 100 (0% to 100%).
Store the PIDA instruction execution status or error status.
For details, see "Operation status (S1+2)" on page 19-19.
Set a value that satisfies alarm 2 value (process low alarm) < alarm 1 value ≤
process variable maximum.
Operates as process variable maximum value when alarm 1 value ≤ alarm 2
value (process low alarm) or alarm 1 value > process variable maximum value.
Set a value that satisfies process variable minimum value ≤ alarm 2 value <
alarm 1 value (process high alarm)
Operates as process variable minimum value when alarm 2 value < process
value minimum value or alarm 1 value (process high alarm) ≤ alarm 2 value.
Set a value between 1 and 10,000 (0.01 to 100.00 seconds).
Sampling period of 0 operates as 0.01 seconds and 10,001 or higher operates
as 100.00 seconds.
Select the control mode.
0: PID control
1: Proportional control
2: PI control
3: PD control
Operates as 0 (PID Control) when a value other than those listed above.
Set a value that satisfies process variable minimum value ≤ set point ≤
process variable maximum value.
When set point < process variable minimum value or process variable
maximum value < set point, a set point configuration error occurs and the
previous set point is retained.
Set a value between 1 and 10,000 (±0.01 to ±100.00%)
Proportional band of 0 operates as ±0.01% and 10,001 or higher operates as
±100.00%.
FC6A S MICROS
ERIES MART
Output manipulated
variable (60%)
ON (3 s) OFF
5 s
Setting Details
L P M
ADDER ROGRAMMING ANUAL
Output manipulated
variable (50%)
ON (2.5 s) OFF
5 s
FC9Y-B1726
ON
R/W
R/W
R
R
R/W
R/W
R/W
R/W
R/W
R/W