Endress+Hauser Preline RN 221N Betriebsanleitung Seite 22

Active barrier
Terminals I+ and I- are supplied as a blue terminal strip on
units supplied as Ex versions. This means that a sensor fitted in
the hazardous area can be directly connected to the unit.
3.5 Connecting further peripheral instrumentation (output)
If there is a possibility of electrical transients on long signal
cable runs we would recommend that an overvoltage protection
unit is used. A current signal is available at the passive output
of the unit, terminals O+, O- and O+H, which can be used for
connection to further instrumentation such as displays, printers,
recorders or PLC systems. The front mounted yellow LED
illuminates when current flows in the output circuit.
2-wire current connection without
®
HART -communication resistance
Please take note of the respective volt drop when including the
communication resistance in the current circuit!
®
The HART
in this case, be directly connected to the two front mounted
communication sockets without any further wiring.
20
2-wire current connection with HART
-communication resistance
-programming up module for sensor setting up can,
®