Table 17-3 Normal Successful Status Display; Table 17-4. Easy-Tune Unsuccessful Status Display - ABB ControlIT 53MC5000 Instruction Manual

17.4 EASY-TUNE SEQUENCE STATUS
Once initiated, the algorithm sets the controller to Manual mode. After a period of settling time, a
step change in controller output is applied and the resulting process response is observed. As
summarized in Tables 17-3 and 17-4, datapoint B387, EASY-TUNE Status, will numerically show
the result of the EASY-TUNE algorithm. Figure 17-1 illustrates this event sequence and correlates
it to the numeric codes in B387.

Table 17-3 Normal Successful Status Display

B387
1 Settling time and finding initial steady state values.
2 Initial step disturbance to the process.
3 Preliminary process characterization. (Disturbance is removed.)
4 Finding second steady state values. (Disturbance is re-applied.)
5 Finding process characteristics. (Disturbance is removed.)
0 EASY-TUNE successfully completed.

Table 17-4. EASY-TUNE Unsuccessful Status Display

B387 Description
51 Controller output was saturated
52 Saturation would have occurred if
EASY-TUNE had continued.
53 PV excursion exceeded the limit.
54 Controller output was altered
externally, either deliberately or
aDIdentally.
55 A time-out occurred when B387 was 1. Increase the Digital Filter Index (B269) and/or the
56 A time-out occurred when B387 was 2. Increase the Limiting Settling Time (C379), or
57 A time-out occurred when B387 was 3. Disturbance might have occurred during EASY-
58 A time-out occurred when B387 was 4. Disturbance might have occurred during EASY-
59 A time-out occurred when B387 was 5. Disturbance might have occurred during EASY-
60 Abort EASY-TUNE Switch, L521 was
set to 1.
61 Tuning parameter limits were
exceeded and used in the controller.
Section 17. EASY-TUNE
Description
Suggested Action/Cause/Retry
Controller output was saturated at the start.
Reverse the sign of step size configured in C381.
Reduce the step size magnitude in C381 or
increase MAX PV excursion limit in C380.
Refrain from changing output.
Limiting Settling Time (C379).
increase Step Size Change in Controller Output
(C381), or decrease Excursion Limit for
Preliminary Step Disturbance (C378).
TUNE sequence.
TUNE sequence.
TUNE sequence.
EASY-TUNE was aborted.
Widen the tuning parameter limits in C385 - C390
or set Enable Tuning Parameter Limits, L520 to 0.
17-3