Vega VEGAPULS 67 Product Information - page 15
15
Electronics - Modbus, Levelmaster protocol
Radar - Level measurement in bulk solids
29427-EN-160312
11 Electronics-Modbus,Levelmasterprotocol
Configurationoftheelectronics
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 contact pins with I²C interface for parameter adjustment are located
on the upper side of the electronics. The terminals for the power supply
are located in the separate connection compartment.
Voltage supply
Power supply via the Modbus host (RTU)
•
Operating voltage
– 8 … 30 V DC
•
max. number of sensors
– 32
Connectioncable
Connection is carried out with screened cable according to Fieldbus
specification.
For power supply, a separate two-wire cable is required.
In the product configurator of VEGAPULS, different cable glands can
be selected. They cover all cable diameters in the range of 4 … 12 mm
(0.16 … 0.47 in).
Make sure that the entire installation is carried out according to the Field-
bus specification. In particular, make sure that the bus is terminated with
suitable terminating resistors.
Cablescreeningandgrounding
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
Doublechamberhousing
+
+
power supply
MODBUS
D0
D1
IS GN
D
USB
1
2
4
3
1
3 4 5
2
off on
( )
(
)
(-)
(-)
Fig. 27: Terminal compartment
1 USB interface
2 Slideswitchforintegratedterminationresistor(120Ω)
3 Voltage supply
4 Modbus signal