User manual - CONTROLLER PUR-94
There are 3 auto-tuning modes available, as a result of which the settings of one of the
controllers will be selected:
The
At-F
mode:
Auto-tuning using both the controller’s control loops (
At-F
mode), during which two
outputs of the device are controlled by two controller loops. In this process, the device
determines (based on the setpoint and the measured value), which loop is to be tuned. The
second loop receives the same settings. When the setpoint is greater than the measured
value, the
PID-H
controller’s loop will be tuned, and when the setpoint is less than the
measured value, the
PID-C
controller’s loop will be tuned.
The process of auto-tuning in this mode may commence subject to the following
conditions:
1) The value measured by the device must be greater than six fifths of the setpoint (when
the
PID-H
controller is tuned) or the value measured by the device must be greater than
six fifths of the setpoint (when the
PID-C
controller will be tuned)
2) The source of at least one of the device’s outputs must be
PidH
if the loop of the
PID-H
controller will be tuned, or the source of at least one of the outputs must be
PidC
,
if the loop of the
PID-C
controller will be tuned. In addition, these outputs can not be set
in the
noAC
mode.
The
At-H
mode:
Auto-tuning of the
PID-H
loop (the
At-H
mode), during which the device uses and adjusts
only that loop. The second loop remains idle and its setting will not change following the
process.
The process of auto-tuning in this mode may commence subject to the following conditions:
1) The value measured by the device must be less than four-fifths of the setpoint,
2) The source of at least one of the device’s outputs must be
Pid-H
. Additionally, those
outputs cannot be set in the
noAC
mode.
The
At-C
mode:
Auto-tuning of the
PID-C
loop (the
At-C
mode), during which the device uses and adjusts
only that loop. The second loop remains idle and its setting will not change following the
process.
The process of auto-tuning in this mode may commence subject to the following conditions:
1) The value measured by the device must be greater than six fifths of the setpoint
2) The source of at least one of the device’s outputs must be
PID-C
. Additionally, those
outputs cannot be set in the
noAC
mode.
Auto-tuning that is already underway is a very sensitive process. So the user should pay
attention to events that could interrupt the tuning of the settings. These events include:
1) Loss of power to the device.
2) Time for auto-tuning exceeded (24 h).
3) When the PID controller’s operating mode is switched over.
4) Measurement error (e.g. sensor failure).
5) Change in the parameters of the device.
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