User's Manual

11
5. RELAY ALARM OUTPUTS (STANDARD
CONFIGURATION)
There are 4 relay alarm outputs (AL1-AL4) on the rear panel.
 AL1 is for system okay,
 AL2 is for concentration limit 1 exceeded and
 AL3 is for concentration limit 2 exceeded.
 AL4 is not used
The relay alarm output AL1 is enabled all the time, whereas the AL2 and AL3 can be
enabled/disabled by going into the diagnostics menu (with 929 password), then factory options, then
turning conc. Alarm Relays ON or OFF.
When the concentration alarm relays are enabled, concentration alarms status is no longer
available through the “Status output” pins. So, either the alarm relays or the status bits could
be used to monitor the concentration alarms but not both at the same time. The default
factory setting is to enable the concentration alarm relays.
The AL1 relay is energized when the system is okay and de-energized when the system has
a fault. The AL2 and AL3 relays energize when the corresponding concentration limits are
exceeded.
6. RELAY ALARM OUTPUTS (AIR PRODUCTS
CONFIGURATION)
There are 4 relay alarm outputs (AL1-AL4) on the rear panel.
 AL1 is for “system okay”,
 AL2 is for “high range status” and
 AL3 is for “zero calibration status”
 AL4 is not used
The AL1 relay is energized when the system is okay and de-energized when the system has
a fault. The AL2 relay is energized when the high auto-range is in use and and AL3 relays
energize when the the instrument is in zero calibration mode.
7. CONTROL INPUTS (AIR PRODUCTS
CONFIGURATION ONLY)
An additional control input is available on this instrument. Control input “C” is used to
select the range for remote calibration. When input C is low, the instrument selects high
range during contact closure calibration.