Red Lion DLC - Manual (Page 13)

13
TEMPERATURE
COOL HEAT
SETPOINT
-100%
O2
+100%
O1
2X PROPORTIONAL
BAND
OUTPUT
POWER ( ) %
O1
+100%
SETPOINT
DEADBAND
NEGATIVE VALUE
POWER ( )
OUTPUT
%
COOL
RELATIVE GAIN = .5
.5 1 2
RELATIVE GAIN
O2
-100%
TEMPERATURE
HEAT
TEMPERATURE
HEAT
SETPOINT
-100%
O2
+100%
O1
DEADBAND
POSITIVE VALUE
POWER ( )
OUTPUT
%
RELATIVE GAIN
2 1 .5
RELATIVE GAIN = .5
COOL
HEAT/COOL RELATIVE GAIN FIGURES
Heat/Cool Deadband = 0
Heat/Cool Deadband < 0
Heat/Cool Deadband > 0
STEP 14 PROGRAMMING THE COOLING
To enable Cooling in Heat/Cool applications, the Alarm 2 Action must first be set for Cooling. When
set to cooling, the output no longer operates as an alarm but operates as an independent cooling output.
The OP2 terminals are the same as AL2. Cooling output power ranges from -100% (full cooling) to 0%
(no cooling, unless a heat/cool deadband overlap is used). The Power Limits in the Output category also
limits the cooling power.
Cycle Time (40141/40241): This cycle time functions like the OP1 Output Cycle Time but allows
independent cycle time for cooling. A setting of zero will keep output OP2 off. The status of OP2 can
be read through registers (40016/40032).
Relative Gain (40142/40242): This defines the gain of the cooling relative to the heating. It is generally
set to balance the effects of cooling to that of heating. This is illustrated in the Heat/Cool Relative Gain
Figures. A value of 0.0 places the cooling output into On/Off Control. This may be done independent
of the OP1 Output PID or On/Off Control Modes.
Deadband (40143/40243): This defines the area in which both heating and cooling are active (negative
value) or the deadband area between the bands (positive value). If a heat/cool overlap is specified, the
percent output power is the sum of the heat power (OP1) and the cool power (OP2). If Relative Gain
is zero, the cooling output operates in the On/Off Control Mode, with the Deadband value becoming
the cooling output hysteresis (positive value only). This is illustrated in the On/Off Control Mode
section. For most applications, set this parameter to 0.0 prior to starting Auto-Tune. After the
completion of Auto-Tune, this parameter may be changed.