Owner manual

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Appendix B: Enhanced Process Control
Typical Applications
This section provides usage examples of the Enhanced features for the
CLS and MLS manuals.
Process Variable Retransmit
The Process Variable Retransmit [PVR] feature provides
retransmission of the process signal of one channel [primary] via the
control output of another channel [secondary]. This signal is a linear
output signal which is proportional to the engineering units of the
primary channel input.
The controller output signal must be connected to a DAC converter in
order to get an analog signal of 4-20 MAdc or 0-5 Vdc. The type of
DAC ordered depends on application requirements.
Some typical uses would be for data logging to older style analog
recording systems, or long distance transmission of the primary signal
to avoid degradation of the primary signal. The signal can also be used
as an input to other types of control systems such as a PLC.
An 8CLS controls the temperature of a furnace. The thermocouple in
one of the zones is connected to the CLS and is used for closed-loop
PID control. An analog recorder data logging system is also in place,
and a recording of the process temperature is required. The recorder
input is a linear 4-20mAdc signal representing a range of 0-1000ºF..