22
1980
2010
-0
2
22
Installation
3.3.1
Wiring Diagrams
Control loop without communication resistor
In this configuration, the field device is powered externally by a PLC, Remote I/O or DC
power supply and outputs a 4 ... 20 mA signal. The adapter provides the following
functions:
•
Current measurement via 4 ... 20 mA interface,
•
If the connected device supports it, HART digital communication.
For communication with the adapter, a HART modem can be connected to terminals 5/7
and 6/8.
For loops with two signal lines, the adapter should be wired as shown in the following figure
(view Figure 3.8 on page 22).
Figure 3.8: Connection of adapter to a control loop without communication resistor
For loops with only one signal line (common ground), the adapter should be wired as
shown in the following figure (view Figure 3.9 on page 23).
Note!
•
The connection is made across the adapter
’
s own 270
communication resistor
•
The circuits in the following 2 figures are electrically identical as terminal 4 and 5 are
connected internally (view Figure 3.8 on page 22, view Figure 3.9 on page 23).
1
PLC, Remote I/O, DC power supply without communication resistor
2
Field device (passive)
1
2
1 2 3 4 5 6
