Rockwell Automation 1769-OF4VI Compact I/O Isolated Analog Modules - Manual (Page 76)

Publication 1769-UM014B-EN-P - May 2010
5-4 Module Diagnostics and Troubleshooting
Open-circuit Detection (1769-IF4I Module Only)
The module performs an open-circuit test on all enabled channels configured
for 4 to 20 mA inputs and for all voltage inputs. Whenever an open-circuit
condition occurs, the under-range bit for that channel is set on all channels
configured for 4 to 20 mA inputs or the over-range bit for that channel is set
on all channels configured for voltage inputs in the Input Data file.
Possible causes of an open circuit include:
 the sensing device may be broken.
 a wire may be loose or cut.
 the sensing device may not be installed on the configured channel.
Non-critical vs. Critical
Module Errors
Non-critical module errors are typically recoverable. Channel errors
(over-range or under-range errors) are non-critical. Non-critical errors are
indicated in the module input data table. Non-critical configuration errors are
indicated by the extended error code.
See 1769-IF4I Extended Error Codes on page 5-6 and 1769-OF4CI and
-OF4VI Extended Error Codes on page 5-8.
Critical module errors are conditions that prevent normal or recoverable
operation of the system. When these types of errors occur, the system typically
leaves the run or program mode of operation until the error can be dealt with.
Critical module errors are indicated in 1769-IF4I Extended Error Codes on
page 5-6 and 1769-OF4CI and -OF4VI Extended Error Codes on page 5-8.
Module Error Definition
Table
Analog module errors are expressed in two fields as four-digit Hex format
with the most significant digit as don’t care and irrelevant. The two fields are
Module Error and Extended Error Information.
Table 5.2 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