Revision 1 72 9/10/2019
5.6.1 Global Alarms
The 13 alarm references and their associated indicators in the upper left corner are referred
to as global alarms. These alarms are non-analysis related alarm parameters that affect all
streams identically and are related to hardware and other physical parameters that affect the
operation of the analyzer. In many cases, the set point for these global alarms is user
configurable. Each alarm can be configured to be active or not active and to trigger certain
outputs, either solenoids or relays.
• High Temperature - The high temperature alarm will be triggered if the temperature
experienced by the sensor block’s on-board temperature sensor exceeds the set-point
value, in
o
C.
• Low Temperature - The Low Temperature alarm will be triggered if the temperature
experienced by the sensor block’s on-board temperature sensor goes below the set-point
value, in
o
C.
• Sensor LED Current - If the sensor current rises above the set-point value, the alarm is
triggered, as there is likely a problem with the sensor block or the sample chamber is dirty.
The set-point for this alarm is configured at the factory and should not be changed.
• Sensor Comm - The sensor communications alarm is an alarm that triggers if the unit is no
longer able to communicate between the motherboard and the sensor block. If this alarm
triggers, the unit will no longer function correctly.
• RTC Battery - The battery alarm will be triggered if the voltage from the on-board clock
battery, which maintains the analyzer’s real-time clock should the power fail or drops below
a hard-coded value. It can also be triggered if an invalid time is detected.
• Maximum Tape Advance - The maximum tape advance alarm will be triggered if the motor
advances the tape more than a certain number of rotations without getting a corresponding
signal from the pulse counter that controls the tape advance. If this alarm triggers, it will
generally indicate a problem with the encoder. The length of the maximum tape advance
can be set by the user, but it is advised to leave this set at the factory default.
• Low Tape - The analyzer can be configured with an optional optical low tape sensor (see
Section x.xx). If this alarm is triggered, it means that the tape is very low and should be
replaced soon. The Low Tape alarm, should it be installed, is triggered when there is
approximately 15 feet of tape remaining on the reel.
• Tape Length - A low tape alarm can also be triggered based on the amount of tape that is
calculated to be remaining by the pulse counter. The alarm will trigger when the length of
tape calculated to be remaining, in feet, drops below the number set in this field. For this
alarm to work correctly, it is essential that the length of tape in the reel be reset to the
correct length value (usually 300 or 350 feet) in the Global tab whenever a tape is replaced.
• Tape Movement - If the pulse counter no longer receives any pulses when the tape is
advanced by the motor, this alarm is triggered. Tape Movement and maximum tape
advance alarms may be triggered by the same problem, so both should be analyzed.
Possible causes of a tape movement alarm include running the analyzer out of tape, tape
breakage, jamming of the encoder, motor failure and improper tape installation.
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