A flow switch provides a discrete input to the PLC. The flow switch is typically used as a method of control in tanks, vessels, pumps and other types of process equipment.
- Abbreviated as FS
Note that like apressure switch, a flow switch is different than a flow transmitter in that a flow switches sole function is to provide a binary TRUE or FALSE into the PLC. This approach simplifies programming.
Flow switches can be solid state or electro=mechanical. They can be mass flow switches or volumetric flow switches and measure gas or liquids.
Configuration and Alarms
Alarms in the PLC can be:
- High - FSH
- Low - FSL
- High/Low - FSHL