(Redirected from ZSL)
ZS
A Position Switch is specified as ZS on instrument bubbles on Piping and Instrumentation Diagram. A position switch provides a discrete input to the PLC. The Position Switch is used to confirm the position of a critical component in the process, often a valve. In processes where valve closure is important, such as during a mixing process, ensuring that the valve is closed is important.
Note that like a pressure switch, a position switch's sole function is to provide a binary TRUE or FALSE into the PLC.
Types
Configuration and Alarms
Alarms in the PLC can be:
- Position
- Open - ZSO
- Closed - ZSC
