
SuperNova PD500 PID Process & Temperature Controllers
Instruction Manual
28
Hysteresis, Heating (HYS) and
Hysteresis, Cooling (HYSC)
When using on/off control, the hysteresis sets the
difference from the on state and the off state of the
heating or heating & cooling outputs.
The output deadband of the heating side and cooling
sides can be set individually.
The deadband during heating & cooling on/off control
is as follows.
Figure 24. Heating & Cooling Hysteresis
Hysteresis (HYS) and Cooling Hysteresis (HYSC) are
displayed only when Out1 Control Mode (CNT1) and
OUT2 Control Mode (CNT2) are programmed for
On/Off (ONOF) control respectively.
Emergency Output, Heating (EO)
and Emergency Output Cooling
(EOC)
This parameter sets the output levels in the case of
internal PV calculation error or an input sensor burn
out error.
The output conditions of EO and EOC according to
the conditions are as follows.
When using only CNT1 (CNT2 as NONE or models
without OUT2 option), emergency output EO is
generated as shown below according to On/Off and
PID settings.
Emergency Output when
Control Output 2 (CNT2) is NONE.
CNT1 Mode On/Off (ONOF) PID
EO or EOC
Range
EO = 0.0%
or EO = 100.0% 0.0
≤
EO
≤
100.0%
OUT1 or OUT
2 Output in
Emergency/
Error State
MV = EO
If OL-L > EO,
(MV = 0.0%)
If OL-H < EO,
MV = OLH
If OL-
L ≤ EO ≤ OL
-H,
MV = EO
When both CNT1 and CNT2 are used, EO and EOC
are generated as follows.
HOUT Emergency Output when Control Output 1
(CNT1) and Control Output 2 (CNT2) in Use
CNT1 Mode On/Off (ONOF) PID
EO Range
EO = 0.0% or
100.0%
0.0 ≤ EO ≤ 100.0
HOUT Output
If OLH < 100.0,
HOUT = 0.0
If OL-H < EO,
HOUT = OL-H
HOUT = EO
If
0 ≤ EO ≤ OL
-H,
HOUT = EO
Note that when using on/off control, if parameter
Output Limit High (OL-H) is set to less than 100%, the
emergency condition output will remain 0%,
regardless of the setting for Emergency Output,
Heating (EO).
COUT Emergency Output when Control Output 1
(CNT1) and Control Output 2 (CNT2) in Use
CNT2 Mode On/Off (ONOF) PID
EOC Range EOC = 0.0% or
100.0%
0.0% ≤ EOC ≤
100.0%
COUT Output
If OLH < 100.0%,
COUT = 0.0%
If OL-H < EOC,
COUT = OL-H
COUT = EO
If
0 ≤ EOC ≤ OL
-H,
COUT = EOC
Note that when using on/off control, if parameter
Output Limit Low (OL-L) is set to less than 100%, the
emergency condition cooling output will remain 0%,
regardless of the setting for Emergency Output,
Cooling (EOC).
Output Limit High (OL-H) and Low
(OL-L)
The output limits high and low restrict the control
output (MV) percent output to greater than the
minimum and less than the maximum output levels.
For models where parameter OUT2 Control Mode
(CNT2) is set to NONE, Output Limit High (OL-H) is
the output high limit and Output Limit Low (OL-L) is
the output low limit. The minimum output is 0%, and
the maximum output is 100%.
If OUT2 Control Mode (CNT2) is not NONE, the OL-H
parameter is the heating output high limit, and the
OL-L is the cooling output high limit.