Watlow Series 920 Microprocessor-Based Ramping Control - Manual (Page 46)

The heating cycle time usually expressed in seconds for a controller to complete one ON/
OFF cycle. Time between successive turn ons. This parameter will not appear if: OUT =
CL, or PB H = 0 or if your Series 920 has a 4-2OmA output and OUT = HT or HT/CL.
Range: 1 to 60 seconds Default: 5
A thermal control band for heating, that defines where the rate (derivative) function begins.
This band is in multiples of the heat proportional band. This parameter will not appear if
OUT=CL, or PB H=0.
Range: 0 to 7 times PB H Default: 0
The area where no heating or cooling takes place in a heat/cool proportional control. Not
displayed if OUT = HT or CL.
Range: -20 to 2O°F, C or Units Default: 0
A temperature band expressed in degrees within which a temperature controller proportion-
ing function is active for cooling. This parameter will not appear if OUT = HT.
Range: 0 to 900°F/0 to 500°C Default: 45°F/25°C
Reset (integral) cooling control action that automatically eliminates offset, or “droop”,
between set point and actual process temperature in a proportional control. Expressed in
repeats per minute. This parameter will not appear if OUT = HT, of PB C = 0.
Range: 0.00 to 5.00 repeats/minute
Default 0.00
The rate (derivative) cooling function of the Series 920. The rate is determined by how fast
the error being corrected is increasing. Expressed in minutes. This parameter will not
appear if OUT=HT, or PB C=O.
Range: 0.00 to 5.00 minutes 0.00
The cooling cycle time expressed in seconds for a controller to complete one ON/OFF
cycle. Time between successive turn ons. This parameter will not appear if: OUT = HT. or
PB C = 0. Your Series 920 has a output and OUT = CL or CL/HT.
Range: 1 to 60 seconds Default: 5
A thermal control band for cooling that defines where the rate (derivative) function begins.
Use the same as RB H. This band is in multipIes of the cool proportional band. This
parameter will not appear if OUT= CL, or PB C = 0.
Range: 0 to 7 times PB C Default: 0
From RETURN, you can go back to the SYSTEM prompt by pressing the ENTER key, or
return to PID by pressing the MODE key.
In the SETUP menu, ACCESS (3) must be selected to enter the MANUAL parameters.
Here you can manually adjust percent power.
When ACCESS (3) is selected under the SETUP mode of the Series 920, the MANUAL
parameters appear. The outputs revert to manual percent power control at the percent of
power that they happen to be currently at.
Allows the operator to manually adjust the percent power output. The default value dis-
played and controlling at, is the value the PID calculated when the MANUAL parameter
menu was entered. -100 to 100 represents full cool to full heat, respectively This parame-
ter will take priority over the LOPWR and HIPWR parameters.
Range: -100 to 100 Default: of power output when MANUAL is entered
46 WATLOW Series 920 User’s Manual How To Program the Series 920, Chapter 6