Cryo-con Model 24C
Basic Setup and Operation
Autotune Menu
+
Sets the loop number for autotuning. Each control loop must be
tuned separately.
#
Sets the maximum power delta allowed during the tuning process.
Value is a percent of full-scale output power.
+
Sets autotuning mode. Choices are P, PI or PID.
#
Sets the autotune timeout in seconds. If the process model has
not converged within this time, tuning is aborted.
Real-time display of the temperature on the input channel being
tuned.
Pressing Enter will initiate the autotune sequence.
Autotune status. Display only
Proportional gain term generated by autotune. This field will be
blank until a successful autotune is completed.
Integral gain term generated by autotune. This field will be blank
until a successful autotune is completed.
Derivative gain term generated by autotune. This field will be
blank until a successful autotune is completed.
Pressing
Enter
cause the controller to transfer the generated PID
coefficients to the selected loop, initiate control with the new
parameters and exit to the Home Operate Display.
Table 30: Autotune Menu
The Delta P field is in percent and is the maximum change in output power that the
controller is allowed to apply during the modeling process. A value of 100% allows
use of full-scale power increments. A value of 20% uses a maximum power increment
of
20% of the current heater output.
The Mode field tells autotune to generate coefficients for P only, PI only, or PID.
Choices are: P--, PI- and PID.
The Timeout field is in units of Seconds and indicates the maximum period of time
that the process model will run before aborting. This value should be set to at least
two or three times the estimated maximum time constant of the process.
i
Note:
Depending on the setup configuration, the autotune
algorithm may apply full-scale heater power to the process for an
extended time. Therefore, care should be taken to ensure that
autotune does not overheat user equipment. If overheating is a
concern, the Over Temperature Disconnect Monitor should be
configured to disconnect the heater and abort the autotune process
when an input temperature exceeds the specified maximum.
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