Watlow Series 935A User’s Manual
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Set the PID Menu Values
•
Proportional Band, Heat and Cool
[Pb`h]
and
[Pb`c]
: Select a value (degrees) to set up band on either side (±) of the
Primary Set Point in which the heat and/or cool proportioning function(s) will be active.
For on/off control, set
[Pb`h]
or
[Pb`c]
= 0.
Range: 0 to 999°F/555°C, or 0.0 to 999.0°F/555.0°C
Default: 25°F/17°C, or 25.0°F/17.0°C
•
Hysteresis, Heat and Cool
[hYSh]
and
[hYSc]
: For use with on/off control only. Select the value (degrees) for the process vari-
able change required to re-energize the control heat and/or cool output.
For ON/off control, set
[Pb`h]
or
[Pb`c]
= 0.
Range: 1 to 999°F/555°C, or 0.1 to 999.0°F/555.0°C
Default: 3°F/2°C, or 3.0°F/2.0°C
•
Cycle Time,
[Ct`h]
and
[Ct`c]
: Select the value (seconds) required for the heat and/or cool output(s) to complete a full ON
through off cycle.
Range: Switched dc/Solid State Relay: 0.1 to 60.0 seconds
Default: 5.0 seconds
Range: Electromechanical Relay: 5.0 to 60.0 seconds
Default: 30.0 seconds
•
Dead Band
[``db]
: Dead Band adjusts the effective cool set point above the primary set point by the Dead Band value in de-
grees. This creates a band between the heating and cooling proportional bands where only integral and derivative activity will
occur. For more information on Dead Band fine tuning, go to p. 33.
Range: 0 to 999°F/555°C, or 0.0 to 999.0°F/555.0°C
Default: 0°
•
Integral
[``It]
: Select a value (minutes/repeat) for the integral function. Integral is the inverse of Reset; It(value) =
1/Reset(value).
Range: 0.00 to 99.99 minutes/repeat
Default: 5.00 minutes/repeat
•
Derivative
[``dE]
: Select a value (minutes) for the derivative function.
Range: 0.00 to 9.99 minutes
Default: 0.00 minutes
•
Calibration Offset
[`CAL]
: Eliminates the difference between the displayed process temperature and the actual process temper-
ature value.
Range: -999 to 9999°F/C, or -99.9 to 999.9F/C
Default: 0°