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4 Operation
Model 1220
4-4
Teledyne Analytical Instruments
4.3 Channel Module Front Panel
Controls and Indicators
STANDBY Switch - When pressed, this membrane switch
places the Channel Module in the standby mode, i.e.,
removes power from the sensor(s) and extinguishes the
LCD display.
NOTE: If the relays are configured for fail-safe operation, they will remain
energized. If an alarm condition exists, the Channel Module will
return to a non-alarm state.
RESET Switch - After an alarm condition is no longer
present, as indicated by the concentration value shown on
the display, press this membrane switch to return the relay
or relays to the non-alarm (normal) state.
BYPASS Switch - When in an alarm condition, pressing
this membrane switch disables the Control Unit audible
alarm.
NOTE: The red, yellow and blue alarm LEDs begin to flash. They remain
flashing until the alarms are reset or the BYPASS switch is pressed
again.
SELECT Switch - Use this membrane switch to access any
of the Channel Module’s four user-configurable modes and
their options. The four modes are:
1. Sensor and Calibration Mode - This mode allows you to
select sensor 1 (S1) or sensor 2 (S2) and then set the
ZERO and SPAN values. It also is used during the
“One-Man” (1MAN) calibration option.
2. Alarm Configuration Mode - This mode allows you to
adjust the set points of the High and/or Caution alarms
as well as define the configuration for the alarms as
“Fail-Safe” / “Non-Fail-safe” and/or “Latching” / “Non-
Latching”.
3. Identification (ID) Code Set Mode - This mode allows
you to define the unique ID for each Channel Module
for use with RS-485 communication (Special option,
contact factory).
4. Passcode Enable/Disable Mode - This mode allows you
to enable or disable the factory-defined passcode.
RESET
BYPASS
SELECT