VersaPro Temperature Controller
Page 13
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5
Process Control Options
The Versapro is configured to perform as a single loop PID controller for a specific process. This instrument is
setup as an oxygen controller.
Table 1 Instrument Control Options
Function
Description
Temperature
Uses the temperature signals from a thermocouple to control to
temperature setpoint.
Linear Input A
Uses the millivolt signal from a linear sensor connected to terminals
+TC / -TC
Linear Input B
Uses the millivolt signal from a linear sensor connected to terminals
+MV / -MV
6 Control
Modes
The VersaPro controller provides:
Time Proportional Single (TP)
Time Proportional Dual (TD)
Time Proportional Compliment (TC)
Position Proportioning (PP)
On/Off
(OF)
On/Off Dual (OD)
On/Off Compliment (OC)
Direct Signal Output (4-20mA)
The instrument controls with two control contacts or direct 4-20mA output from two analog output channels.
The control function can be set to direct acting or reverse acting.
Direct acting increases the output control signal to increase the process. Reverse acting decreases the output
control signal to increase the process.
6.1
Time Proportioning (TP)
Time proportioning adjusts the duty cycle of the control device to maintain control. This is usually done with
solenoid valves controlling the flow of a trim gas or addition air to the process. The control loop percent output
is the percentage of the ON time relative to total cycle time. The cycle time is the ON time plus OFF time.
For example if the control loop percent output is 34% and the cycle time is 10 seconds, then the ON time
would be 3.4 seconds and the OFF time would be 6.6 seconds. The selection of the proper cycle time is a
tradeoff between excess wear and tear on the solenoid valve with short cycle times or oscillation of the control
process using long cycle times. Only the first control contact is used in this mode.
