Samson 3730-6, Mounting And Operating Instructions

Page: 49 / 124

5.2.2 Establishing communication
Communication between PC and positioner
(via FSK modem or handheld communicator,
if necessary, using an isolation amplifier) is
based on the HART
®
protocol.
Type Viator FSK modem
RS 232 not ex. Order no. 8812-0130
PCMCIA not ex Order no. 8812-0131
USB not ex Order no. 8812-0132
If the supply voltage of the controller or con-
trol station becomes too low because it has
been reduced by the load in the circuit, an
isolation amplifier is to be connected be-
tween controller and positioner (interfacing
as for positioner connected in hazardous ar-
eas, see Fig. 19).
If the positioner is used in hazardous areas,
an explosion-protected isolating amplifier is
to be used.
By means of the 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
EB 8384-6 EN
49
Connections
3730-6
3730-6
Fig. 19 · Connection with FSK modem
Explosion-protected isolating amplifier
Connection in safe area
Handheld communicator
or second FSK modem
Handheld communicator
or second FSK modem (explosion-protected)
4 to 20 mA
Safe area
Hazardous area
Controller/control station
Controller/control station
Connection in hazardous area