Emerson OCX 8800 Instruction Manual page 53

Instruction Manual
IM-106-880, Rev 1.0
January 2007
Figure 5-2. Signal Line Connections,
< 250 Ohms Load Resistance
4-20 mA Terminal Block in
Electronics Housing
A OUT 1 +
A OUT 1 -
Method 2, for Load Resistance < 250 Ohms
Refer to Figure 5-2 and the following steps to connect the HART
communicator to a signal line with less than 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.
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).
1
O 4-20 mA Signal Line
2
Loop
Connectors
HART Communicator
Rear Panel
Analog Output Device
HART
Communicator
Model 275/375
NOTE: The signal loop must be broken to insert
the optional 250 ohm load resistor.
OCX 8800
RL <250Ω
250 OHM
Load Resistor
(See Note)
5-3