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GF U3000 V2 Ultrasonic Flowmeter
Modbus Supplement to the operating instructions
1
Intended use
The type GF U3000 V2 Ultrasonic Flowmeter Modbus document is a supplement to the operating instructions.
2
MODBUS CONNECTIONS
The ideal Modbus network topology is that of a daisy chain as depicted in Figure 2. Small spurs may be used, but in this case attention
needs to be paid to the data rate and the number of units on the bus. It is recommended to run cable containing 4 wires and a shield
to each GF U3000 V2 Ultrasonic Flowmeter from a network junction box. This accommodates one pair of twisted wires into the con-
nected unit, and one set out to connect to the next unit.
It is the responsibility of the user to install cable and wire to the MULTICOMP MP002510 Modbus plug connector. The connection
diagram is shown below in Figure 1. Note that the connection polarity is all important. It is the user’s responsibility to ensure that the
A/+ve and B/-ve connections to all units are consistent.
1
2
3
GND
A / +ve
B / -ve
Rear View of Multicomp Pro
MULTICOMP MP002510
Rear Solder Lug View
G2.1 Figure 1 - GF U3000 V2 Ultrasonic Flowmeter Modbus Plug Connections
For reliable operation of a Modbus network the cable type and installation must comply with requirements in the Modbus specifica-
tion document:
MODBUS over Serial Line Specification & Implementation guide V1.02
CAUTION!
This output is suitable for SELV circuits only!
For full immunity to electrical interference the screen of the Modbus cable should be connected to Earth.
