Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001

19.2 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,

  1. - Communication errors
  2. - PLC power on, first scan
  3. - Data retention -- PLC restarts with same outputs stopped with
  4. - Battery low
  5. - Scan time too long error
  6. - I/O error -- problem with one of the I/O cards
  7. - etc.