Omron SYSMAC C200HS Operation Manual page 253

Special Math Instructions
Parameter Settings
Set value (SV)
Proportional band
Tik
Tdk
Sampling period
PID
forward/reverse
designation
2-PID parameter
(α)
Input range
Output range
PID CONTROL Operation
PID Control Method
Item
This is the target value of the process being
controlled.
This is the parameter for P control expressing
the proportional control range/total control
range.
This is a constant expressing the strength of
the integral operation. As this value increases,
the integral strength decreases.
This is a constant expressing the strength of
the derivative operation. As this value
increases, the derivative strength increases.
This sets the period for executing the PID
operation.
This is the parameter that determines the
direction of the proportional operation.
This is the input filter coefficient. Normally use
0.65 (i.e., a setting of 000). The filter efficiency
decreases as the coefficient approaches 0.
This is the number of input data bits.
This is the number of output data bits. {The
number of output bits is automatically the same
as the number of input bits.)
Execution Condition OFF
All data that has been set is retained. Then the execution condition is OFF, the
operation amount can be written to the output word (D) to achieve manual con-
trol.
Rising Edge of the Execution Condition
The work area is initialized based on the PID parameters that have been set and
the PID control operation is begin. Sudden and radical changes in the operation
output amount are not made when starting operation to avoid adverse affect on
the controlled system (bumpless operation).
When PID parameters are changed, they first become valid when the execution
condition changes from OFF to ON.
Execution Condition ON
The PID operation is executed at the intervals based on the sampling period,
according to the PID parameters that have been set.
Sampling Period and PID Execution Timing
The sampling period is the time interval to retrieve the measurement data for
carrying out a PID operation. PID(––), however, is executed according to
C200HS cycle time, so there may be cases where the sampling period is ex-
ceeded. In such cases, the time interval until the next sampling is reduced.
C200HS PID control operations are executed by means of PID control with feed-
forward control (two degrees of freedom).
Contents
Section 5-21
Setting range
Binary data (of the same
number of bits as specified for
the input range)
0001 to 9999 (4 digits BCD);
(0.1% to 999.9%, in units of
0.1%)
0001 to 8191 (4 digits BCD);
(9999 = Integral operation not
executed)
0000 to 8191 (4 digits BCD)
0001 to 1023 (4 digits BCD);
(0.1 to 102.3 s, in units of
0.1 s)
0: Reverse operation
1: Forward operation
000: α = 0.65
Setting from 100 to 199 means
that the value of the rightmost
two digits is set from α= 0.00
to α= 0.99.
0: 8 bits 5: 13 bits
1: 9 bits 1: 9 bits 6: 14 bits 6: 14 bits
2: 10 bits 7: 15 bits
3: 11 bits 8: 16 bits
4: 12 bits
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