Precision Digital PD6870 - Manual (Page 12)

PD6870 Loop-Powered Process Meter Instruction Manual
12
Connections & Wiring Diagrams
Signal connections are made to a three-terminal connector mounted on the rear of
the display module. The enclosure also provides one internal and one external earth
grounding screw. The 4-20 mA input with no backlight has a maximum voltage drop
of 1 V and is wired as shown in Figure 2. The loop-powered backlight configuration
requires a total maximum voltage drop of 4 V. The backlight option is recommended
for dim lighting conditions and is enabled when wired as shown in Figure 3.
Figure 2. PD6870 Input Connections without Backlight
Figure 3. PD6870 Input Connections with Loop-Powered Backlight