Table 29 - Bad Channel Diagnostics - Honeywell HC900 Installation And User Manual

Diagnostics and Troubleshooting - User Interface
Bad I/O Channel Diagnostics
Below is a list of conditions that can cause a bad channel diagnostic. The associated function block's I/O
status will indicate the nature of the diagnostic described in the failure column.
Module Failure
Type
AI Burnout Failure
Under range
Over range
Failing to
convert
AO Channel
Failure
134

Table 29 - Bad Channel Diagnostics

Description
The sensor – T/C, RTD, or mV source --
is failing burnout checks.
The signal at the terminals is less than
10% below the range of the sensor.
The signal at the terminals is more than
10% over the range of the sensor.
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.
The board indicates that the channel is
failing to output the correct value.
HC900 Hybrid Controller Installation and User Guide
User Action
Check terminal block
1.
connections
Replace source
2.
element
Replace card.
3.
Check the signal level
1.
being applied to the
terminals.
Replace card.
2.
Check the signal level
1.
being applied to the
terminals.
Replace card.
2.
Check the signal level
1.
being applied to the
terminals.
Replace card.
2.
Check terminal
1.
connections.
Replace module.
2.
Revision 5
9/03