C5-5
IM 34M06H62-02E 2nd Edition : June 2008-00
C5.2.1 Tuning Points and Stored PID Number
Setting the Start Auto-tuning (AT) parameter to an integer value ranging from 1 to 5 starts
auto-tuning. Setting AT to 1, 2, 3 or 4 performs tuning for 1.PID to 4.PID respectively.
Setting AT to 5 performs auto-tuning for 1.PID to 4.PID sequentially.
The auto-tuning operation turns on or turns off the output when the PV passes through a
tuning point. If the Zone PID Selection (ZONE) is set to 1 (Enabled), setting AT to 5
calculates the PID values using the mean values of successive reference points (1RP,
2RP) as tuning points.
Auto-tuning updates the following PID values: Proportional Band (PB), Integral Time (TI),
Derivative Time (TD) and Cooling Gain (GAIN.C). The following table shows which PID
parameter group is updated.
Table C5.4 Tuning Point and Stored PID Number (1/2)
(when Zone PID Selection (ZONE) = 0 (Disabled))
AT Tuning Point
*1, *2
PID Parameter Group for Storing AT Results
1 Set Point (1.SP) 1.PID
2 Set Point (2.SP) 2.PID
3 Set Point (3.SP) 3.PID
4 Set Point (4.SP) 4.PID
5
3
(1) Set Point (1.SP) 1.PID
(2) Set Point (2.SP) 2.PID
(3) Set Point (3.SP) 3.PID
(4) Set Point (4.SP) 4.PID
*1 Tuning points are limited within 3% to 97% of the input range. The upper and lower range limits are RH and RL for
thermocouple and RTD input; SH and SL for direct voltage input and PRH and PRL for two-input changeover control.
*2 If the Remote/Local Selection (RMT/LOC) is set to “Remote”, the Remote Set Point (RSP) is used as the tuning point.
*3 If AT=5, auto-tuning is performed successively for set points (1), (2), (3) and (4).
Table C5.4 Tuning Point and Stored PID Number (2/2)
(when Zone PID Selection (ZONE) = 1(Enabled))
AT Tuning Point
*1
PID Parameter Group for Storing AT Results
1 Control set point (CSP) 1.PID
2 Control set point (CSP) 2.PID
3 Control set point (CSP) 3.PID
4 Control set point (CSP) 4.PID
5
2
(1) (1RP – Lower range limit) / 2 1.PID
(2) (2RP – 1RP) / 2 2.PID
(3) (Upper range limit – 2RP) / 2 3.PID
(4) (Upper range limit – lower range limit) / 2 4.PID
*1 Tuning points are limited to within 3% to 97% of the input range. The upper and lower range limits are RH and RL for
thermocouple and RTD input; SH and SL for direct voltage input and PRH and PRL in two-input changeover control
mode.
*2 If AT=5, auto-tuning is performed successively for set points (1), (2), (3) and (4).
If auto-tuning is executed during an increase or decrease of the CSP due to the SP
gradient function, the current set point (1.SP to 4.SP) or the Remote Set Point (RSP) is
used as the tuning point. CSP also changes to the current set point value.
To Next Page
Loading...
Need help?
General
