Rockwell Automation 1757-ABRIO Process Remote I/O (RIO) Communication Interface Module - Manual (Page 149)

Publication 1757-UM007D-EN-P - December 2008 147
Operational Comparison Between the 1757-ABRIO Module and a PLC-5 System Appendix B
Analog input voltage or current out
of valid over/under range for
channel configuration Underrange or overrange bit for the channel is set
Input data for the channel in the tag is set to NaN
Set status bit.
Write NaN (Not a Number) to one
element of a numeric write tag from
a ProcessLogix controller Value that has NaN sets the output to the configured
fault value
The block transfer continues to update
The remaining values in the tag continue to be written
correctly
Overrange bit for the channel is set
N/A
Write to or read from tag that
doesn't exist Message gets an error status
DDE or OPC server item has bad quality
N/A
Write beyond end of tag Message gets an error indicating the length or offset is
incorrect
DDE or OPC server item has bad quality
N/A
Write to or read from a tag that has
one (faulted) module mapped to it Read or write message succeeds
Data from faulted input module is set to NaN
State of outputs on faulted output module depend on
the module configuration
N/A
Write to or read from a tag that has
multiple modules mapped to it, only
one module faulted Read or write message succeeds
Data for non-faulted modules continues to update
correctly.
N/A
Read from or write to tag that has
nothing mapped to it Read or write message fails, empty tags are not
downloaded to the 1757-ABRIO module. N/A
OPC/DDE reads or writes tags but
control program has died or gone
away 1757-ABRIO module continues in ACTIVE mode
The output values are the last values written by the
control program, or the values written by DDE/OPC
N/A
(1) In a ProcessLogix file, seen as NaN.
In an RSLogix 5000 file, seen as 1.#QNAN (the controller has a function that detects this)
In the ABRIO Monitor, seen as 1.#QNB.
Exception Conditions Comparison Between a PLC-5 System and a 1757-ABRIO Module
Exception Condition Message From 1757-ABRIO Perspective From the PLC-5 Perspective