Samson 3731-3 - Establishing HART Communication

5.2.1 Establishing communication
Communication between PC and the FSK
modem or handheld communicator and
positioner is based on the HART
®
protocol.
Type Viator FSK modem
RS-232
USB
not ex
not ex
Order no. 8812-0130
Order no. 8812-0132
If the load impedance of the controller or
control station is too low, an isolation ampli
-
fier functioning as load converter is to be
connected between controller and
positioner.
Thanks to HART
®
protocol all control room
and field devices connected in the loop are
individually accessible through their address
via point-to-point or standard bus
(Multidrop).
Point-to-point:
The bus address/polling address must al
-
ways be set to zero (0).
Standard bus (Multidrop):
In the standard bus (Multidrop) mode, the
positioner follows the analog current signal
(reference variable) as for point-to-point
communication. This operating mode is, for
example, suitable for split-range operation
of positioners (series connection). The bus
address/polling address has to be within a
range of 1 to 15.
40 EB 8387-3 EN
Connections
3731-30
3731-31
Fig. 13 · Connection with a FSK modem
Connection in non-hazardous area
Hazardous area
Handheld communicator
or second FSK modem
Controller/control station
Controller/control station
Handheld communicator
or second FSK modem (explosion-protected)
Connection in hazardous area
Safe area
FSK modem
4 to 20 mA
Ex isolating amplifier
FSK modem