Bus Wiring Of Several Load Cells; External Power Supply - HBM C16i Série Notice De Montage

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9.1 Bus wiring of several load cells

The bus wiring of several load cells come into being by joining together the
connection cables' core ends with identical colours. HBM recommend the use
of a junction box without dropping resistors (e.g. VKK2--6).
Wiring code
TA (TX--)
TB (TX+)
RA (RX--)
RB (RX+)
UB
GND
PC
9.2

External power supply

The load cell features a digital output with RS--485 (4--wire) interface. For the
power supply an external DC supply voltage is required.
Power supply unit selection for C16i...:
Procedure for selecting a suitable power supply unit to supply power to the in-
terface converter and the connected C16i... load cells:
1. Determine the required cable length between power supply unit and junc-
tion box by examining the actual on site situation.
2. In the table below, read off actual power consumption values in relation to
the number of load cells used.
3. Select cable cross--section in the relevant line such that the required cable
length can be implemented. With a 15 VDC nominal voltage, it is always
possible to implement longer cables or smaller wire cross--sections than
with a 12 VDC rating.
4. Read off voltage and minimum current for the (plug--in type) power supply
unit required. The power supply unit should be electronically controlled.
HBM
RS-485 / 4 wire BUS
C16i ...
C16i...
C16i ...
A1461--1.2 de/en/fr