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I/O Module Diagnostics and I/O Calibration
Diagnostics
Revision 9
900 Control Station User Guide
47
May 2014
Number of
Strobes
Failure
Description
AI AO DI
DO
PFQ User Action
Contact AC DC Relay AC DC
11
Shift Register
The loopback test of the shift
register failed.
√
√
√
√
√
√
Replace module
Bad channel details
Below is a list of conditions that can cause a BAD CHANNEL I/O module diagnostic.
Table 24 Bad Channel details
I/O Summary Error Status
Description
What to do
Bad Channel
If the channel is an Analog Output: There is no
physical output device connected to this
channel, or the output device is showing an
open connection.
If the channel is a Pulse Output: The channel is
failing to output the correct value.
A BAD CHANNEL I/O module diagnostic is
posted.
Check terminal block
connections.
Replace module.
Burnout Fail
The sensor – T/C, RTD, or mV source -- is
failing burnout checks. A BAD CHANNEL I/O
module diagnostic is posted.
Check terminal block connections
Replace source element
Replace module.
Convert Fail
When attempting to take a reading, the analog-
to-digital (ADC) fails. This can occur if the
incoming signal is either too large or too 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. A BAD
CHANNEL I/O module diagnostic is posted.
Check the signal level being
applied to the terminals.
Replace module.
No Channel
There is no hardware on the I/O module to
support this channel. For example, the
customer configured Channel #15 for a given
module, but there is an 8-channel module
installed in the rack. A BAD CHANNEL I/O
module diagnostic is posted.
Over Current
A Digital Output module detected an excessive
amount of current on its output terminals. Note
that this message will only appear for the 32-
channel DO module. A BAD CHANNEL module
diagnostic is posted.