RKC INSTRUMENT Z-TIO-G, Instruction Manual

Page: 180 / 246

9. COMMUNICATION DATA DESCRIPTION
IMS01T28-E4
9-72
Output change rate limiter (up)
RKC communication
identifier
PH
Modbus
register address
ch1: 0262H (610)
ch2: 0263H (611)
Output change rate limiter (down) RKC communication
identifier
PL
Modbus
register address
ch1: 0266H (614)
ch2: 0267H (615)
Set the Output change rate limiter (up, down) that limits change in the output.
Attribute:
R/W
Digits:
7 digits
Number of data:
2 (Data of each channel)
Data range:
0.0 to 100.0 % /second of manipulated output (0.0: OFF)
Factory set value:
Output change rate limiter (up): 0.0
Output change rate limiter (down): 0.0
Related parameters:
Output limiter high/low (P. 9-73)
Function:
The Output change rate limiter limits the variation of Manipulated output (MV) per
second. This function is suitable for an application in which a sudden MV change is not
acceptable.
[The output change rate limiter is effective
.]

The MV reaches 100 % when the power is turned on to the controller and such a sudden output change is
not acceptable in the application.

A sudden output change occurs at the SV change and it is not acceptable in the application.
Output limiter high
100 %
Manipulated output (MV)

Sudden
variation of
output
When the output change rate limiter is disabled
MV
MV
0.0 to
100.0 % of
manipulated
output
1 second
Set the amount of increase given to the
operation output in the percentage of
manipulated output for each second.
Sudden change in the output at power-up, set value
change or by disturbance
Output limiter low
0 %
Manipulated output (MV)

The output changes at specific rates set by Output change rate limiter (up) even under the situations where
a sudden output change would occur without Output change rate limiter function. There is also independent
Output change rate limiter (down).
If the Output change rate is set smaller, it will cause slow control response and affect Derivative
action.
When the Output change rate limiter is used, you may not be able to obtain appropriate PID
constants by Autotuning.
The Output change rate limiter is particularly effective when a sudden MV change may create
uncontrollable situation cause a large current flow. Also, it is very effective current output or
voltage output is used as control output.