User manual

Publication 1768-UM001C-EN-P - November 2007
78 Develop Applications
Determining if Communication has Timed Out with Any Device
If communication times out with at least one device (module) in the I/O
configuration of the controller, the I/O status indicator on the front of the
controller flashes green.
• The GSV instruction gets the status of the I/O status indicator and
stores it in the I_O_LED tag
• If the I_O_LED tag equals 2, the controller has lost communication
with at least one device
where:
I_O_LED is a DINT tag that stores the status of the I/O status
indicator on the front of the controller.