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Operation
-
Using
Accutune II
140
DR4500A Classic Series Circular Chart Recorder With or Without Control Product Manual
Release M
April 2017
Using Accutune with Duplex (Heat/Cool) Control
“TUNE” can be done for applications using Duplex (Heat/Cool) control.
During tuning, Accutune II assumes SP 1 will cause a Heating demand, and then the calculated tuning
parameters will be automatically entered as the first set of PID constants. Likewise, it assumes tuning at
Local SP 2 will cause a Cooling demand, and the cooling parameters will be entered as the second set of
PID constants.
Procedure
After “TUNE” has been enabled in the Tuning Set Up group as described in section 4, use the procedure in
Table 5-24 to start tuning. Note that control group parameter “SP SOURC” must be set to “2LOCAL” to
enable the second setpoint.
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 5-24 Procedure for using Accutune for duplex control
Step
Press
Action/Result
Heating Tuning
1
DISP
Until you see Setpoint 1.
Lower Display:
SP nnn
2
or
Until the value of Setpoint 1 is at the desired value within the Heat
zone.
Make sure the recorder is in Auto mode. (“A” indicator lit.)
If not, use the
MAN/AUTO
key to put the unit in Auto.
3
DISP
Until you see
Lower Display:
UseSPn
This is the prompt used to select the setpoint. If it is not
“USESP1”, use
or
to switch to “USESP1”.
4
DISP
Until you see
Lower Display:
TUNExOFF
x
= 1 or 2
If “TUNExOFF” (tune off) does not appear, then Accutune is not
enabled.
5
or
to toggle to
Lower Display:
TUNExON
x
= 1 or 2
Tuning will begin and the lower display will flash “TUNING”. The
output will cycle between 50% and 100% (or high output limit).
When tuning has been completed the lower display will again
show “TUNExOFF”. The Heat tuning parameters are entered for
the first set of PID constants in the Tuning Set Up group.