Granville-Phillips Series 330, Instruction Manual, Page: 27 / 76

3 Operation
27
Series 330 Vacuum Gauge Controller
Instruction Manual - 330004 - Rev. 02
3.1.2 Power ON/OFF
To turn ON the 330 VGC, depress the top half of the power switch located on the rear panel. A
green LED on the front panel illuminates when the power is ON.
To turn OFF the VGC, depress the lower half of the power switch.
NOTE: There is NO power switch for the Convectron or thermocouple gauges.
When the VGC is turned ON the Convectron or thermocouple gauges are ON.
3.1.3 Ion Gauge ON/OFF
The ionization gauge can be turned ON or OFF with the front panel momentary rocker switch or by
remote control.
To turn ON the ion gauge from the front panel, press the momentary rocker switch See Figure 3-1.
To turn it OFF, press the switch again. The gauge ON indicator is the digital display on the front
panel. The display will turn ON immediately and display 9.9+9. After an approximately 2 seconds,
the actual pressure will be displayed.
NOTE: The maximum voltage appearing on the gauge tube contacts will be
5.5 Vdc when the ion gauge is OFF.
3.1.4 Degas ON/OFF
The I
2
R degas can be turned ON or OFF by the front panel momentary rocker switch (Figure 3-1) or
the remote control input. To turn degas ON, press the DEGAS momentary rocker switch. An LED on
the front panel illuminates when degas is ON. To turn it OFF, press the rocker switch again or press
the GAUGE momentary rocker switch to turn OFF degas and turn ON the gauge.
Degas cannot be activated unless the gauge is first turned ON and indicated system pressure is
below 5 x 10
-5
Torr. This prevents degas turn-on at pressures tat are too high for the gauge
materials, or where degas is of no practical use. Pressure measurement is not possible during degas.
NOTE: During degas, the digital display will turn OFF.
3.1.5 Remote Input/Output
Two TTL compatible inputs are provided through the rear panel allowing control of the ion gauge
and degas. The function of the front panel keys is reproduced by either a contact closure or an
asserted low (0V) logic state on these inputs. This low state must be held continuously for at least 25
milliseconds. After this, the input must be allowed to pull high for at least 105 milliseconds before
another low will be accepted. These inputs have passive pull-ups.
A single-pole, double-throw relay is provided to indicate filament status (the normally open contact
is open when the filament is OFF). Refer to Table 3-1.
Table 3-1 Series 330 Remote Input/Output Connector for the Ion Gauge
Pin Number Function Pin Number Function
1 Gauge On/Off Remote* 6 Degas On/Off Remote*
2 Ground 7 Ground
3 Not Used 8 Not Used
4 Gauge Status Common 9 Gauge Status N.O. (Normally Open)
5 Gauge Status N.C. (Normally Closed)
*Active low inputs