Message instructions, Appendix b, Appendix – Rockwell Automation 1734-IE4S POINT Guard I/O Safety Modules User Manual User Manual

Page 155

Advertising
background image

Rockwell Automation Publication 1734-UM013J-EN-P - July 2014

155

Appendix

B

Get I/O Diagnostic Status from Modules in Logix
Systems

You can use message instructions in a Logix system to determine the cause of
input point or output point faults.

Message Instructions

When the controller detects a fault on an input or output point, you can use a
message instruction to explicitly retrieve the cause of the fault.

In this example, we use a 1734-OB8S module with the Input Status set to return
Point Status. This table illustrates the controller tags that you can monitor for
this module.

Use the Point Output Status bits to detect if one or more of the output points on
the module have a fault:

If any status bit goes to a value of 0 (0 = error, 1 = no error), use the status

bit to condition your message instruction as follows.

Place these rungs in the standard task.

Topic

Page

Message Instructions

155

Configure the Message Instruction

156

Class, Instance, and Attribute Data for I/O Modules

157

Advertising