Precision Digital PD540 - Manual (Page 20)

Fig 3: Time-Proportional PID Control Output
3 Sec
CT = 10 Sec
5 Sec
Output at 50% Output at 70% Output at 30%
5 Sec 7 Sec 3 Sec 7 Sec
CT = 10 Sec CT = 10 Sec
PV
This parameter establishes reverse (REV) or forward (FWD) activation of the control
outputs. In forward operation, the control outputs will be most active when the PV value is
higher than the SP, as the controller acts to lower the PV. In reverse operation, the control
outputs will be most active when the PV value is lower than the SP value, as the controller
acts to inc rease the PV. The default setting is REV.
This parameter sets a high limit for the levels of the control output. This limits the output
levels based on a percentage of their full scale. Its default setting is 100 (%).
This parameter sets hysteresis in case of On/Off control output mode in a H/C model.
PV
This parameter establishes the cycle time for use with time-proportional PID relay or
voltage pulse control when the outputs are set to HEAT or COOL. The cycle time can be
set from 1 to 300 seconds. Its default setting is 2 seconds.
PV
PV
This parameter sets a low limit for the levels of the control output. This prevents the
outputs from dropping below a certain level based on a percentage of their full scale. Its
default setting is 0 (%). The outputs are limited by both the the low and high limits.
PV
This parameter establishes the cycle time for cooling outputs if cooling (COOL) control is
set up with time-proportional PID control in a H/C model. (Example: OUT1 = Cool, OUT2
or Out3 = Cool and set to SSR, SUB1 or SUB2 = Cool) The cycle time can be set from 1
to 300 seconds. Its default setting is 2 seconds.
PV
This parameter sets the hysteresis high limit for on/off relay control mode in normal
models (non -Heating/Cooling models).
This parameter sets the hysteresis low limit for on/off relay control mode in normal models
(non-Heating/Cooling models).
PV
PV
Cycle Time (CT) set to 10 seconds
o.Act
ct
ctC
oH
oL
HYS
HYS.H
HYS.L
PD540 Series Nova Digital Process and Temperature Controller Instruction Manual
20