Digital Signals; Digital Zero; Signal Freeze And Resume - Agilent Technologies 7820A Advanced User's Manual

7
GC Output Signals

Digital Signals

Digital zero

Signal Freeze and Resume

122
The GC outputs digital signals only to an Agilent data system.
The following discussions describe features that impact the data
sent to data systems, not the analog data available to
integrators. Access these features from the data system. These
features are not accessible from the GC keypad.
Available only from an Agilent data system.
Digital signal outputs respond to a zero command by
subtracting the signal level at the time of the command from all
future values.
Available only from an Agilent data system.
Some run time operations, such as changing signal assignments
or switching a valve, can cause baseline upsets. Other factors
can cause baseline upsets also. The GC can compensate for this
by pausing (freezing) the signal at a particular value, using that
signal value for a specified duration, and then resuming normal
signal output.
Consider a system that uses a switching valve. When the valve
switches, an anomaly occurs in the baseline. By freezing and
resuming the signal, the anomaly can be removed so that the
peak identification and integration software operates more
smoothly.
Advanced User Guide