Vega VEGAPULS 68 - Electronics - Foundation Fieldbus

14
Electronics - Foundation Fieldbus
Radar - Level measurement in bulk solids
29427-EN-160312
10 Electronics-FoundationFieldbus
Congurationoftheelectronics
The plug-in electronics is mounted in the electronics compartment of the
instrument and can be exchanged by the user when servicing is required.
The electronics is completely encapsulated to protect against vibration
and moisture.
The terminals for voltage supply as well as the plug with I²C interface for
parameter adjustment are located on the upper side of the electronics. In
the double-chamber housing, these connection elements are located in
the separate terminal compartment.
Voltage supply
Power supply via the H1 Fieldbus cable.
Specications of the voltage supply:
•
Operating voltage
– 9 … 32 V DC
•
max. number of sensors
– 32
Connectioncable
Connection is carried out with screened cable according to Fieldbus
specication.
Make sure that the entire installation is carried out according to the Field-
bus specication. In particular, make sure that the bus is terminated with
suitable terminating resistors.
Cablescreeningandgrounding
In systems with potential equalisation, connect the cable screen directly
to ground potential at the power supply unit, in the connection box and
at the sensor. The screen in the sensor must be connected directly to
the internal ground terminal. The ground terminal outside on the housing
must be connected to the potential equalisation (low impedance).
In systems without potential equalisation, connect the cable screen di-
rectly to ground potential on the power supply unit and the sensor. In the
connection box or T-distributor, the screen of the short stub to the sensor
may not be connected to ground potential or to another cable screen.
Connection
Singlechamberhousing
1
2
( )
(-)
1
5
0
1
0
1
+
678
Bus
2
3
4
5
Fig. 25: Electronics and terminal compartment, single chamber housing
1 Voltage supply/Signal output
2 Contact pins for the display and adjustment module or interface adapter
3 Selection switch for bus address
4 For external display and adjustment unit
5 Ground terminal for connection of the cable screen
Doublechamberhousing
Bus
5
1
2
+
( )
(-)
678
2
3
4
1
Fig. 26: Terminal compartment, double chamber housing
1 Voltage supply, signal output
2 For display and adjustment module or interface adapter
3 For external display and adjustment unit
4 Ground terminal for connection of the cable screen