Rockwell Automation 1756-L6x_L7x ControlLogix System User Manual - Manual (Page 163)

Rockwell Automation Publication 1756-UM001O-EN-P - October 2014 163
Develop Applications Chapter 10
Determine if I/O Communication has Timed Out
This example can be used with the 1756-L7 x or 1756-L6x controllers:
• The GSV instruction gets the status of the I/O status indicator (via the
LEDStatus attribute of the Module object) and stores it in the
IO_LED tag.
• IO_LED is a DINT tag that stores the status of the I/O status indicator or
status display on the front of the controller.
• If IO_LED equals 2, then at least one I/O connection has been lost and
the Fault_Alert is set.
Figure 40 - GSV Used to Identify I/O Timeout
For more information about attributes available with the Module object, see the
Logix5000 Controllers General Instructions Reference Manual, publication
1756-RM003 .
Determine if I/O Communication to a Specific I/O Module has
Timed Out
If communication times out with a device (module) in the I/O configuration of
the controller, the controller produces a fault code and fault information for the
module. You can use GSV instructions to get fault code and information via the
FaultCode and FaultInfo attributes of the Module object.
For more information about attributes available with the Module object, see the
Logix5000 Controllers General Instructions Reference Manual, publication
1756-RM003 .