65-2643RK0504SS M2A Transmitter Operator’s Manual
23
•
When the M2A’s gas type is changed, the M2A will enter Configuration Mode for you to verify the
parameter settings. When you exit Configuration Mode, the display will indicate
NEEDS CALIBRATION
and will continue to indicate this until Calibration Mode is entered and a calibration is performed. In this
situation, the signal output will be fixed at 17.4 mA from the time Gas Type Mode is entered until the M2A
is calibrated and returns to normal operation.
•
If you enter Calibration Mode, Configuration Mode, Gas Type Mode, or Modbus Mode, the signal output
will be fixed at 17.4 mA until the M2A returns to normal operation.
•
If the M2A’s input power decreases below 9.5 volts so that the M2A is in a low power alarm, the signal
output is fixed below 2.4 mA until the low power alarm is cleared.
•
If the M2A goes into a fail condition, after a 30 second delay, the signal output is fixed below 2.4 mA until
the fail alarm is cleared. During the 30 second delay, the signal output follows the detector output. In the
case of a downscale reading, the display and the signal output continue to track the reading down to -99% of
full scale (1.15 mA).
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 26 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.
Table 4: Visual and Audible Alarm Indications
Condition
Cause
Visual Indication(s)
Alarm 1
1
Decreasing gas reading at or below 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.
