50
Analog Output Example Analog outputs from a PLC are often supplied directly or
through signal converters or transmitters to control valves,
instruments, electronic drives or other control devices which
respond to analog signals.
For example, analog outputs from the PLC could be used to
control the flow of fluid in a process by controlling AC drives.
Rather than simply turning the AC drives on or off, which could
be accomplished by discrete outputs, analog signals can be
used to control the output of the AC drives. This would allow
the speed of the pumps to be varied dynamically in response to
changes in process requirements.
Central
Processing
Unit
(CPU)
Analog
Input
Analog
Outputs
PLC
Signal from
Level Transmitter
To Pump 1
To Pump 2
AC Drives
Level
Transmitter
Pump 1
Pump 2
Storage
Tank
Process
To Next Page
Loading...
