PPI Zenex Plus, User Manual, Page: 11 / 27

9
Zenex Plus User Manual
ON-OFF
PID
(Default : PID)
0.1 to 99.9
(Default : 0.2)
SUPERVISORY CONTROL
(Available for Heat Only / Heat+Cool Control Strategy)
Set ‘Yes’ to activate and ‘No’ to abort the Tuning operation.
TUNE >>
This parameter sets the minimum limit on the Control Setpoint
value.
SETPOINT LO LIMIT >>
(Default : No)
Yes
No
Parameter Description
Settings
(Default Value)
SETPOINT HI LIMIT >>
This parameter sets the maximum limit on the Control Setpoint
value.
For Thermocouple Input :
Setpoint LO Limit to 9999
For RTD Input :
Setpoint LO Limit to 600.0
(Default : 600.0)
COMPRESSOR HYST >>
(Available for ‘Cool Only’ ‘Heat + Cool’ Control & with
Compressor PV based Strategy)
Differential (dead) band between the compressor ON and OFF
states.
0.1 to 99.9
(Default : 2.0)
COMPRESSOR SETPOINT >>
(Available for ‘Heat + Cool’ Control Compressor PV with
based Strategy)
This Setpoint Value is compared with the process value to switch
the compressor On/Off with the set compressor hysteresis.
(Default : 45.0)
0.0 to 100.0
For Thermocouple Input :
-200 to Setpoint HI Limit
For RTD Input :
-99.9 to Setpoint HI Limit
(Default : 0.0)
HEAT CTRL ACTION >>
(Available for ‘Heat Only’ & ‘Heat+Cool’ Control Strategy)
On-Off
The control algorithm tends to maintain the PV at SP by either
switching the output (say, Heater) fully OFF or fully ON. The On
and Off switching is differentiated by the user settable ‘Hysteresis
Band’.
PID
The control algorithm uses a 2nd order equation to compute the
‘% Output Power’ required to maintain the PV at SP. The constants
P, I, D are automatically set by the controller.
HEAT HYST >>
(Available for ‘ON-OFF’ Heat Control Action)
Sets a differential (dead) band between the ON and OFF states.
Keep it large enough to avoid frequent switching of the load
without losing the desired control accuracy.