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Chapter 4: Operation
65-2646XL-05-04 M2A Transmitter Operator’s Manual
Alarm Indications
NOTE:
The M2A includes alarm on and alarm off delay settings for alarm 1 and alarm 2. The
alarm indications described in this section operate according to the factory set alarm
settings. See Table 5 on page 31 for all the factory settings.
NOTE:
You can select normally energized (N. EN) or normally de-energized (N. DE-EN) alarm
1 and alarm 2 relay settings in Configuration Mode. The following sections describe the
standard factory setting for these relays which is N. DE-EN.
The fail relay is factory set as N. EN and is not user-adjustable.
Alarm 1 Condition
Alarm 1 Condition Indications
When the gas reading reaches the alarm 1 setpoint, the M2A senses an alarm 1 condition. The
M2A alerts you to an alarm 1 condition as follows:
• The A1 LED turns on.
• The gas reading alternates with the
ALARM-1
message.
• The alarm 1 relay energizes.
Table 4: Visual and Audible Alarm Indications
Condition
Cause
Visual Indication(s)
Alarm 1
1
Increasing gas reading at or above the
alarm 1 setpoint
• A1 LED is on
• Gas reading alternates
with
ALARM-1
message
Alarm 2
1
Increasing gas reading at or above the
alarm 2 setpoint
• A2 LED is on
• Gas reading alternates
with
ALARM-2
message
Fail
• Disconnected or misconnected
detector wiring
• Display reading at -10% of full
scale or lower
• Defective components
• F LED is on
•
FAIL
message replaces
gas reading
NOTE: There is a 30 second
delay on the fail condition.
Low Power
DC power source less than 9.5 volts.
• F LED is on
•
LowPower
message and
actual voltage of incoming
DC power
1
If the M2A is in both an alarm 1 and an alarm 2 condition, both alarm LEDs are on and the
display alternates between the gas reading and the ALMS 1&2 message.
