ProtEX-MAX PD8-765 Explosion-Proof Process & Temperature Meter
Instruction Manual
34
4-20 mA Output & Input Signal
Connections
The PD8-765, with an optional 4-20 mA output, can
be used as an isolated temperature transmitter with a
big display by converting the thermocouple or RTD
input into an isolated 4-20 mA output.
Connections for the 4-20 mA transmitter output are
made to the connector terminals labeled
“mA OUT: I-, I+”. The 4-20 mA output may be
powered from an internal power supply (optional) or
from an external power supply.
Figure 22. 4-20 mA Output & Input Signal
Powered by PD8-765-6X3-20
Figure 23. 4-20 mA Output Signal
Powered by PD8-765-6X5-10
Figure 24. 4-20 mA Output Powered Externally
Models include PD8-765-6X3-00, PD8-765-7X3-00,
PD8-765-7X5-00
Other Uses for Transmitter Power
Supplies
The most common use for the PD8-765
’s two power
supplies is for the 200 mA transmitter power supply to
power the field transmitter and the other power supply
to power the 4-20 mA output from the meter.
However, the power supplies can be used in other
ways. For instance, for level transmitters that require
the use of a heated lens, the PD8-765
’s 200 mA
power supply could be used to power both the heated
lens and the 4-20 mA signal from the transmitter.
Figure 25. PD8-765-6X5-10 Powers Both the Heater
and 4-20 mA Input Signal
External Button Contacts
The PD8-765 is equipped with four external button
contacts that can be used to remotely operate the
PD8-
765’s front panel buttons. For instance, these
button contacts can be used to program the meter
and to remotely acknowledge/reset the relays:
Terminal Programming Operation
M
Menu
R
Right Arrow
Reset Max/Min
U
Up Arrow
Display Max/Min
E
Enter
Acknowledge Relays
COM
SIGNAL CONNECTOR
mA+
2
1
3
5
4
V+
T+
EXC
2-Wire
4-20 mA
Transmitter
-
+
I-
mA OUT
P2-
P1+
4
5
3
1
2
P2+
P1-
24V OUT
6
I+
Remote Display,
Chart Recorder,
etc.
+
-
