Owner's Manual

GDX-350 Sensor Transmitter
P/N: 5600-9001 Rev 2 5
1. OVERVIEW
1.1. Stand-alone and Wired Networks
The GDX-350 is a fixed-point monitor designed to provide continuous monitoring of hazardous gases in
the workplace. Monitored values are displayed in their engineering units as well as graphically such as
bar graphs or 30-minute trends (see Figure 1-1).
Figure 1-1: Engineering Units Data Displays: Bar Graph (Left), 30-Minute Trend (Right)
Input types include electrochemical toxic and oxygen sensors, catalytic bead combustible sensors, MOS
solid-state sensors, as well as various millivolt, volt and 4-20 mA inputs. Sensors supplied by the factory
include an 8-wire Smart Sensor interface capable of configuring data uploads to the GDX-350.
Traditional 3-wire Simple sensors, without the smart interface, are also supported by the GDX-350. Its
advanced microcontroller electronics and superior graphic LCD operator interface offer enhanced
diagnostics and fault analysis not possible in competing products. The GDX-350 provides a standard
4-20 mA output signal for connection to control systems or other alarm instrumentation. Available options
include an Alarm Relay/RS-485-Modbus board or an isolated 4-20 mA output. Non-volatile memory
retains all configuration data during power interruptions. The magnetic, non-intrusive calibration can be
easily performed by a single person without opening the enclosure. A standard Real Time Clock and
Calendar feature allows data logging of calibrations and alarm events for recall to the LCD readout or
over the serial port.
Only periodic calibration checks are needed to assure dependable performance. The operator interface
is very intuitive with the LCD displaying data both graphically as bar-graphs/trends as well as in
engineering units (Figure 1-1). Additional features include:
• No potentiometer or jumper settings required. All setup is completed through display menus
accessed via the LCD/magnetic keypad operator interface without opening the enclosure.
• Field adjustable alarm levels may be high, low, fault, fail-safe, latching and acknowledgeable.
• New alarms cause front LEDs to flash and become steady after acknowledgement.
• CAL MODE advises when to apply gas during calibrations.
• One half-hour trend screen shows rate of change of gas exposures.
• Sensor life bar-graph automatically updates after each SPAN calibration.
• Modular design allows for efficient installation as well as plug in sensors that allow a change in target
gas after installation
• New smart sensors are recognized by the GDX-350 and prompt users to either upload new
configuration data or continue with data from the previous smart sensor.
• Sensors are industry proven for fast response and long life.