Invisible Systems Limited
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7-9 Beetham Road, Milnthorpe Cumbria, LA7 7QL, England
Phone: 01539 722 520 Email: info@invisible-systems.com
QC0150 Mains Powered Modbus Transmitter
Installation Manual
RS485 Connections
The connection from the Modbus Transmitter (RS485) shall only be connected to low
voltage (SELV) circuits. The maximum operating voltage for an RS485 network is 12Vdc.
Cables with a minimum of 1 twisted pair + 1 single core with an overall shield should be
used. A twisted pair should be used for network lines A(+) and B(‐) and a single core or
second twisted pair for 0V. Many specialist cables are available for RS485 but shielded CAT
5e cable (4 twisted pairs) may also be used.
Cables running within the electrical enclosure may come close to high voltages and
therefore must be insulated to the following minimum specification:
RS485 Cables: UL 1015,
105 DegC , 600Vac. 30‐14 AWG.
7.
Examples of Metering Equipment that is compatible with the
modbus equipment
.
Several different types of Modbus Devices are available;
Schneider PM750
The Sequence below shows how to record/change the values in the meter.
