Edwards APGX-H, Instruction Manual, Page: 18 / 32

D023-92-880 Issue F
Page 12 © Edwards Limited 2018. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Operation
To read the voltage at which the set-point output signals are activated, press the ' SET TRIP ' switch (see Figure 5 )
with an appropriate tool. The output of the gauge will indicate the set-point level for 3 seconds after which the
output will read the normal voltage output.
To adjust the voltage at which the set-point output signal is activated, press the '
SET TRIP
' switch and hold it down
for more than 3 seconds. The set-point voltage will start scrolling upwards. Release the switch as soon as you reach
the desired trip voltage. To make finer adjustment, release the '
SET TRIP
' switch just before the desired set-point
voltage is reached and immediately depress the switch as many times as required. Each depression will increase the
set-point voltage by approximately 10 mV. When the set-point voltage reaches 9.3 V it will jump to 1.8 V and increase
again. Refer to
Section 4.1 to determine the operating voltage which corresponds to a given pressure.
The APGX-H has an error monitoring facility, which ensures that the set-point output signal is off:

For approximately 2 seconds immediately after the APGX-H is switched ON

When the pressure output signal is out of range

When an error voltage is detected. See Section 4.3 .
If required the set-point operating voltage can be adjusted to 1.8 V. This ensures that the set-point output is
permanently off.
If required, the set-point signal can be used to indicate when the gauge is operating correctly. Adjust the set-point
operating voltage to greater than 9.2 V. The set-point output will then be ON if the gauge is operating normally, and
OFF if an error condition is detected.
4.3 Error monitoring
If an error occurs during operation of the APGX-H, then the status LED will turn red to indicate an error. Refer to
Section 5.4 for a fault finding guide.
The error condition is reset (cleared) when the power to the gauge is removed.
Table 2 - Error Indication
The set-point will be disabled as soon as one of the above errors is detected.
Error Condition Output Voltage AGC Output TIC Output
Broken filament 9.5 V ERR E Filament Fail
Calibration error 9.6 V ERR F Cal Error
Tube disconnected 9.7 V NOTUBE No Tube