User guide

Valves 11
Advanced User Guide 345
Controlling a Valve
From the keyboard
Valves (except multiposition valves) have two positions
controlled by the [On] and [Off] keys. The keyboard commands
for two- position valves are:
[Valve #] <scroll to the valve> [On] Rotates valve to one stop
and
[Valve #] <scroll to the valve> [Off] Rotates valve to the other
stop
From the run or clock time tables
The Valve On and Valve Off commands can be run time or clock
time programmed. See “Run Time Programming” on page 14
and “Clock Time Programming” on page 17.
If a valve is rotated by a run time program, it is not
automatically returned to its initial position at the end of the
run. You must program this reset operation yourself.
Simple valve: column selection
This is the plumbing for a single valve, configured as a switching
valve, that selects one of two columns for analysis. It has no
configuration parameters.
The column is selected by pressing:
[Valve #] <scroll to valve #> [On] (for the front column) or [Off]
(for the back column).
Front column
Back column
To detect or
From inlet or
sampling valve
ON
OFF