Programming; Run Time Programming; Using Run Time Events - Agilent Technologies 7820A Advanced User's Manual

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Programming

Run Time Programming

Using run time events

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Run time programming during a method allows certain
setpoints to change automatically during a run as a function of
the chromatographic run time. Thus an event that is
programmed to occur at 2 minutes will occur 2 minutes after
every injection.
Its uses include:
• Controlling column switching or other valves
• Changing analog signal definition, zero, or range
• Controlling an auxiliary pressure channel
• Changing polarity of a thermal conductivity detector (TCD)
• Turning the hydrogen flow to a nitrogen-phosphorus
detector (NPD) on or off
• Switching digital signal output (requires an Agilent data
system)
• Pausing ("freezing") and resuming digital signal output
(requires an Agilent data system)
The changes are entered into a run table that specifies the
setpoint to be changed, the time for the change, and the new
value. At the end of the chromatographic run, most setpoints
changed by a run time table are returned to their original
values.
Valves can be run time programmed but are not restored to
their starting position at the end of the run. You must program
the reset operation in the run table if this action is desired. See
"From the run or clock time tables"
The [Run Table] key is used to program the following timed
events.
• Valves (1-2)
• Analog signal definition, zero, and range
• TCD negative polarity (on/off)
• Detector gas flow (on/off), including NPD H
on page 115.
fuel gas
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Advanced User Guide