1.2 PLC STATUS

 

• The PLC keeps track of its status, for internal use, as well as allowing use by the ladder logic.

 

• Some of the status flags available in PLC’s are,

- Communication errors

- PLC power on, first scan

- Data retention -- PLC restarts with same outputs stopped with

- Battery low

- Scan time too long error

- I/O error -- problem with one of the I/O cards

- etc.