Emerson ROSEMOUNT OCX 8800 - Manual (Page 47)

Instruction Manual
IM-106-880, Rev 1.0
January 2007
4-3
OCX 8800
Method 2, for Load Resistance < 250 Ohms
Refer to Figure 4-2 and the following steps to connect the HART
communicator to a signal line with less than 250 ohms load resistance.
1. At a convenient point, break the oxygen analog output 4-20 mA signal
line and install the optional 250 ohm load resistor.
2. Plug the load resistor into the loop connectors (located on the rear panel
of the HART communicator).
Figure 4-2. Signal Line Connections,
< 250 Ohms Load Resistance
Do not make connections to the HART communicator's serial port, 4-20 mA signal lines, or
NiCad recharger jack in an explosive atmosphere. Explosions can result in death or serious
injury.
250 OHM
Load Resistor
(See Note)
37390021
The signal loop must be broken to insert
the optional 250 ohm load resistor. NOTE:
Loop
Connectors
O 4-20 mA Signal Line
2
HART
Communicator
Model 275/375
RL <250 Ω
Analog Output Device
HART Communicator
Rear Panel
4-20 mA Terminal Block in
Electronics Housing
A OUT 1 -
A OUT 1 +
1