Cryo-con Model 24C
Front Panel Menu Operation
PID Tables Menu
The Model 24C can store six user generated PID tables. Each table may have up to
sixteen setpoint zones.
Each setpoint zone in a table requires the entry of a setpoint along with corresponding
values for P, I, D and full-scale heater range.
When controlling in the Table mode, the Model 24C will derive control loop PID
coefficients and heater range by interpolation of the PID Table zones based on that
zone’s setpoint.
PID Tables can be used with both control loops.
Building a table from the front panel requires the entry of several numeric values. For
this reason, the user may want to consider using one of the remote interfaces.
The start, and top level, of this process is the PID Tables menu. Two menu screens
below this are used to enter numeric data. Here is an overview of the process:
1. The PID Tables menu is used to select the PID Table number (zero
through three).
2. Once the table is identified, selecting the EDIT PID TABLE line will take the
menu used to edit individual lines of the selected table.
3. To enter or edit an entry, set the desired entry index and enter the zone
data on the following lines.
4. The last line of this menu is used to save the table when the entire table is
complete.
When a table is saved, it is automatically conditioned so that it can be used directly by
the control loop software. The conditioning deletes all entries with setpoint values of
zero or less and sorts the table based on setpoint. Therefore, an entry may be deleted
by setting the setpoint to any negative number.
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