Digital Signals; Digital Zero; Signal Freeze And Resume - Agilent Technologies 7890 Series Advanced Operation Manual

7
GC Output Signals

Digital Signals

Digital zero

Signal Freeze and Resume

232
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 Operation Manual