
Installation
2
0
1
7
-0
5
23
Figure 3.11
Alternative method of connection of adapter to a control loop without communication
resistor
Control loop with 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. Alternatively it is used in HART multidrop mode. The
adapter provides the following functions:
■
HART digital communication
For communication with the adapter, an Ex ia certified HART modem can be connected to
terminals 5/7 and 6/8.
Existing installations
: For existing installations, we recommend that the adapter is wired as
shown in the following figure.
1
PLC, Remote I/O, DC power supply without communication resistor
2
Field device (passive)
Note!
The circuits in the following 2 figures are electrically identical as terminal 4 is connected
internally to terminal 5 and terminal 3 is connected internally to terminal 6.
see Figure 3.12 on page 24
see Figure 3.13 on page 24