DM-634C Oxygen Sensor Assembly
DM-634C O2 Sensor Instruction Manual Rev. .066
Page 17 of 25
3.9
Programming Alarms
3.9.1
Alarm Levels
Both alarm 1 and alarm 2 levels are factory set prior to shipment. Alarm 1 is set at 19.5%; alarm 2 at 17.5%.
Both alarms can be set in 0.1% increments from 2.5% to 22.5%. The following procedure is used to change
alarm set points:
a)
First, enter the programming menu by holding the programming magnet stationary over “PGM 2” for
30 seconds until the display reads
“VIEW PROG STATUS”
, then withdraw the magnet. At this point
you can scroll through the programming menu by momentarily waving the programming magnet over
“PGM 1” or “PGM 2”. The menu options are: View Program Status, Set Alarm 1 Level, Set Alarm 2
Level. and Set Cal Level. back to normal operations by holding the programming magnet over “PGM
2” for 3 seconds, or automatically return to normal operation in 30 seconds.
b)
ALARM 1 LEVEL From the programming menu scroll to the alarm 1 level listing. The menu item
appears as:
“SET ALARM 1 LEVEL”
. Enter the menu by holding the programming magnet
stationary over “PGM 1” for 3 seconds until the display reads
“SET ALM1 @ 19.5%”
, then withdraw
the magnet. Use the programming magnet to make an adjustment to “PGM 1” to increase or “PGM 2”
to decrease the display reading until the reading is equal to the desired alarm set point. Exit to the
programming menu by holding the programming magnet over “PGM1” for 3 seconds, or automatically
return to the programming menu in 30 seconds.
c)
ALARM 2 LEVEL From the programming menu scroll to the alarm 2 level listing. The menu item
appears as:
“SET ALARM 2 LEVEL”
. Enter the menu by holding the programming magnet
stationary over “PGM 1” for 3 seconds until the display reads
“SET ALM2 @ 17.5%”
, then withdraw
the magnet. Use the programming magnet to make an adjustment to “PGM 1” to increase or “PGM 2”
to decrease the display reading until the reading is equal to the desired alarm set point. Exit to the
programming menu by holding the programming magnet over “PGM1” for 3 seconds, or automatically
return to the programming menu in 30 seconds.
d)
Exit back to normal operations by holding the programming magnet over “PGM 2” for 3 seconds, or
automatically return to normal operation in 30 seconds.
3.9.2
Alarm Reset
An alarm condition will cause the applicable alarm to activate its corresponding relay and LED. If alarm 1,
alarm 2, or fault alarms have been programmed for latching relays, an alarm reset function must be activated
to reset the alarms after an alarm condition has cleared. To reset the alarms, simply wave the programming
magnet over either “PGM 1” or “PGM 2”, momentarily, while in normal operations mode and note that the
corresponding alarm LED(s) turn off.
3.9.3
Other Alarm Functions
Alarms are factory programmed to be non-latching, de-energized; and to fire under ascending gas conditions.
The fault alarm relay is programmed as normally energized which is useful for detecting a 24VDC power
source failure. All alarm functions are programmable via jumper tabs. Changing alarm functions requires the
sensor housing to be opened, thus declassification of the area is required. See section 3.5.4-e for details.
