Rockwell Automation 1794-OB16D FLEX I/O Diagnostic Modules User Manual - Manual (Page 29)

27 Publication 1794-UM061A-EN-P - July 2006
Chapter
3
About the FLEX I/O Diagnostic Output Module
Introduction
In this chapter, you will learn about the diagnostic output module, cat. no.
1794-OB16D.
About the 1794-OB16D
Diagnostic Output Module
The 1794-OB16D diagnostic output module provides sixteen 24V dc sourcing
outputs with open-wire, short-circuit, and user supply reverse polarity
diagnostic features. The module monitors current and voltage at each output
channel.
The module detects:
• an open fault if no current is present at the output terminal.
• a short fault if no voltage is present at the output terminal.
• a reverse-polarity fault if reverse voltage is applied.
When an open or short fault is detected:
• the corresponding channels red indicator is illuminated.
• the module’s red fault indicator is illuminated.
• the module’s open or short error bit is set.
• the module error bit is set.
When a user supply reverse-polarity fault is detected:
• the modules red fault indicator is turned on,
• and the reverse error bit is set.
• the module error bit is set.
For Information About See Page
About the 1794-OB16D Diagnostic Output Module 27
Diagnostic Fault Detection 29
Module Protection Functions 30
Module Limitations 32
Configure Your Output Diagnostic Module 32