Valve Control; The Valve Drivers; The Internal Valve Drivers - Agilent Technologies 7890 Series Advanced Operation Manual

Valve Control

The valve drivers

Table 55 Valve drivers
Valve number Type
1, 2, 3, and 4 Current source
5 and 6 Current source
7 and 8 Contact closure

The internal valve drivers

Advanced Operation Manual
Valves can be controlled manually from the keyboard or as
part of a clock or run time program. Note that only sampling
valves automatically reset at the end of a run. Other valve
types remain at the new position until activated again. For
other valve types, you must include any desired resets in the
program.
A valve driver is the software and circuitry in the GC that
controls a valve or related function. There are eight drivers
known as Valve 1 through Valve 8.
Volts
24 VDC
24 VDC
48 VDC or 48 VAC
RMS
Valve drivers 1 through 4 are usually used to control
pneumatically operated valves mounted in the valve box.
The wiring for these appears at a set of connectors inside
the right cover of the GC.
Pneumatically driven valves are controlled by solenoids
mounted near the connectors that control the flow of air to
the valve actuators.
Power or current Use
13 watts Pneumatic valve
control
100 mA Relays and low-power
devices
Control an external
current source
6
Valves
217