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Operation
-
Using
Accutune II
Release M
DR4500A Classic Series Circular Chart Recorder With or Without Control Product Manual
139
April 2017
5.10 Using Accutune II
Introduction
Accutune II provides foolproof, trouble-free on-demand tuning in the recorder. No knowledge of the
process is required at start-up. The operator simply enters the desired setpoint and initiates the tuning. The
recorder immediately starts controlling to the setpoint while it identifies the process, calculates the tuning
constants and enters them into the tuning set up group, and begins PID control with the correct tuning
parameters. This works with any process, including integrating type processes, and allows retuning at a
fixed setpoint. The tuning sequence will cycle the recorder’s output two full cycles between 0% and 100%
(or low and high output limits) while allowing only a very small process variable change above and below
the setpoint during each cycle.
Accutune works for all control algorithms except ON/OFF.
The recorder must be in Auto mode.
Accutune works for integrating processes.
Enable/disable Accutune using the Tuning Set Up group TUNE parameter described in Section 4.
Detailed instructions for using Accutune follow.
Starting and Stopping Tuning with Accutune II
After “TUNE” has been enabled in the tuning set up group as described in Section 4, use the procedure in
81H
Table 5-23 to start tuning.
To abort tuning in progress, press the
MAN/AUTO
key to take the recorder out of Auto mode. The
message “AbRT” (abort) will be displayed as the value of tuning set up group parameter “AT ERR”. The
tuning parameters will retain the values they had at the start of the Accutune operation.
Table 5-23 Procedure for starting Accutune II
Step
Press
Action/Result
1
DISP
Until you see
Lower Display:
TUNExOFF
x
= 1 or 2
If “TUNExOFF” (tune off) does not appear, then Accutune is not
enabled.
2
or
to toggle to
Lower Display:
TUNExON
x
= 1 or 2
Tuning will begin and the lower display will flash “TUNING”.
When tuning has been ompleted the lower display will again show
“TUNExOFF”.