Rockwell Automation 1769-IR6 Compact I/O 1769-IR6 RTD/Resistance Input Module - Manual (Page 84)

84 Rockwell Automation Publication 1769-UM005B-EN-P - March 2012
Chapter 5 Diagnostics and Troubleshooting
Open-Wire or Short-Circuit Detection
The module performs an open-circuit or short-circuit input test on all enabled
channels on each scan. Whenever an open-circuit or short-circuit condition
occurs, the broken input bit for that channel is set in input data word 6.
Possible causes of a broken input condition include:
· the input device is broken
· a wire is loose or cut
· the input device is not installed on the configured channel
· an RTD is internally shorted
· an RTD is not installed correctly
Non-critical versus Critical
Module Errors Non-critical module errors are typically recoverable. Channel errors (over-
range or under-range errors) are non-critical. Non-critical error conditions are
indicated in the module input data table. Non-critical configuration errors are
indicated by the extended error code. See Table 24 Extended Error Codes on
page 87.
Critical module errors are conditions that may prevent normal or recoverable
operation of the system. When these types of errors occur, the system typically
leaves the run mode of operation until the error can be dealt with. Critical
module errors are indicated in Table 24 Extended Error Codes on page 87.
Module Error Definition
Table Module errors are expressed in two fields as four-digit Hex format with the
most significant digit as irrelevant (“don’t care”). The two fields are “Module
Error” and “Extended Error Information”. The structure of the module error
data is shown below.
TIP See Open-Circuit Flag Bits (OC0…OC5) on page 49.
Table 22 - Module Error Table
“Don’t Care” Bits Module Error Extended Error Information
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Hex Digit 4 Hex Digit 3 Hex Digit 2 Hex Digit 1