Honeywell ControlEdge 900 platform, Hardware Planning And Installation Manual, Page: 175 / 230

175
Bad I/O Channel Diagnostics
Individual channels on I/O modules indicate their diagnostics by 6
flashes on the EPM and CPM; the channel’s LED does not indicate a
diagnostic. Table below is a list of conditions that can cause a bad
channel diagnostic.
Table 8-4: Bad I/O Channel Diagnostics
Module
Type
Failure
message
indicate don
configuration
tool
Description User Action
AI Burnout
Failure The sensor – T/C, RTD, or mV source -- is
failing burnout checks. Check
terminal
block
connections
Under range The signal at the terminals is less than 10%
below the range of the sensor. Check the
signal level
being
applied to
the
terminals.
Over range The signal at the terminals is more than 10%
over the range of the sensor. Check the
signal level
being
applied to
the
terminals.
Failing to
convert When attempting to take a reading, the ADC
fails. This could result if the incoming signal
is either too large or small. It also could
result if the ADC circuit is failing. If the
problem is the ADC circuit, most likely other
channels will have the same failure. Check the
signal level
being
applied to
the
terminals.
AO Bad Channel The board indicates that the channel is failing
to output the correct value. Check
terminal
connections.
DO Bad Channel The number of configured channels in the
DO function block exceeds the number of
hardware channels on the DO card. Reconfigure
the DO
function
block.
Chapter 8 - Diagnostics and Troubleshooting