Instrument Diagnostics - Honeywell CM4 Technical Handbook

CM4 Four-Point Continuous Monitor

1.7 Instrument Diagnostics

The CM4 provides diagnostic instrument fault and maintenance
requirement indications. These activate one of the following:
• One or both fault relays activate
• On-board memory stores most recent eight fault events for
later recall
• Fault information is sent to the printer (if enabled)
• Status LEDs light yellow for the appropriate point to indicate
instrument faults
• The display shows the fault information
• If the fault generated is an instrument fault and the CM4 is
appropriately configured, the current level on the optional analog
4-20 mA output port is reduced to 2 mA.
Condition
Monitoring
Level 1 alarm
Level 2 alarm
Low Chemcassette maintenance fault (monitoring continues)
(See Appendix B)
Power interruption or CPU fault
Instrument Fault (monitoring continues on unaffected points)
Instrument fault
(monitoring suspended)
CM4 Technical Manual
Point Point
Status LED Alarm LED
Green OFF
Red - Low level alarm for affected point
Green
(steady) - General low level alarm
- High and low level alarms for
Flashing
Green affected point
red
- General high and low level alarms
Green OFF Maintenance fault
OFF or OFF or
Watchdog fault
random random
Yellow OFF Instrument fault
Yellow OFF Instrument fault
Table 1-1: Instrument Alarms
1-8
Relays Beeping
Activated Audio Alarm
All OFF OFF
ON
ON
OFF
OFF
OFF
OFF
Display
Current concentrations (each point displayed for four
seconds)
Current concentrations
Current concentrations
Current concentrations followed by fault message (as
last message in sequence)
Blank or random
Current concentrations followed by fault message (as
last message in sequence)
Fault Message