GDS-68XP Operation & Maintenance Manual, Revision 3.4
Page 26
GASMAX CONTROLS A ND DIS PLAY
There are four magnetic switches on the face of the GASMAX CX,
arranged in a quadrant around the LCD display. Starting in the upper
left and proceeding clockwise these are labeled UP, NEXT, EDIT and
DN/CAL. To activate, or “press” a magnetic switch, swipe the magnet
near the switch. For the balance of this manual, the term “press” will
be used to describe activation of any key via the magnetic wand.
Below the LCD display, two LEDs monitor the MODBUS RS-485 or
Ethernet network interface. Flashing indicates sent or received data.
The
EDIT
key activates the USER MENU mode (See Chapter 8). During USER MENU mode, the UP, DN and
NEXT keys are used to select and confirm menu entries. The USER MENU allows the operator to view the
Event Log and channel parameters and change system settings such as alarm levels and real time clock
day and date.
Pressing the
DOWN/CAL
key, followed by the EDIT key, initiates calibration mode. For a detailed
description of calibration, see Chapter 6.
Pressing the
NEXT
key momentarily causes the GDS-68XP display to sequence display screens between
DUAL DISPLAY, RAW SENSOR TREND, PPM OUTPUT TREND, RAW SENSOR, and PPM OUTPUT.
Figure 6-4: GDS-68XP GASMAX Display Sequence
RAW SENSOR
displays the calibrated gas value being read by the sensor at any moment. As such, it will
increase when the 3-way valve opens to allow sample gas into the unit, and will then drop back to zero
during purge and purge / hold. Use the Raw Sensor Trend screen to monitor the sensor’s response to
sample gas.
PPM OUTPUT
displays and holds the maximum value found during the most recent sample sequence.
Its value is updated each time the sequencer identifies a new maximum ppm value.
DUAL DISPLAY
shows both RAW SENSOR and PPM OUPTUT values on a single screen.