Owner's Manual

GDX-350 Sensor Transmitter
26 P/N: 5600-9001 Rev 2
2.10. Isolated 4-20 mA Output Option
The optional Isolated 4-20 mA option (P/N 5600-0009) as shown in Figure 2-11 provides dual 4-20 mA
outputs that are electrically isolated from sensor inputs and the 24 VDC power source. Each 4-20 mA
output shares the same common terminal and are not isolated from one another. This board is
“piggybacked” behind the Display Assembly (P/N 5600-0005) as seen in Figure 2-2. Addition of this
option requires 4-wire mode 4-20 mA operation and thereby requires the use of an I/O Power Supply
board (Figure 2-8).
Figure 2-11: Isolated 4-20 mA Output Option (P/N 5600-0009)
2.11. Sensor Installation
The GDX-350 Smart Sensor interface uses proven electrochemical technology for toxic/oxygen and
catalytic bead for LEL. In addition, a tiny memory IC is incorporated into GDX-350 factory supplied Smart
sensors allowing them to contain the entire database of GDX-350 parameters onboard the replaceable
Smart Sensor assembly (Figure 2-12).
Electrochemical and catalytic bead smart sensors both plug into the Smart Sensor Head that connects to
GDX-350 electronics with its 8-conductor Smart Sensor Interface cable (Figure 2-12).
Figure 2-12: Smart Sensor Head Assembly