POWER SUPPLY
MeterBUS PORT
RS485 SERIAL PORT
RS232 SERIAL PORT
The power supply source must
be protected from any module
malfunctions using appropriately-sized
safety fuses.
5/6
ELECTRICAL CONNECTIONS
10
11
Vac / Vdc
Vac / Vdc
MeterBUS
MeterBUS
A (+)
B (-)
GND
1
2
3
4
5
CONNECTION STANDARDS
MeterBUS is a non-polarized bus.
For the connection it is possible to use a two-wire shielded telephone cable or an unshielded duplex cable following the
indications in the table.
If a shielded cable is used, this must be
connected to earth only from the R-KEY-MBUS side.
Type of
installation
Maximum
speed
Connection
maximum distance
Connection
total length
Type of cable
Small in house
38400
< 350 m
< 1000 m
0.5 mm
2
, R < 30 Ω
Large in house
9600
< 350 m
< 3000 m
0.5 mm
2
, R < 30 Ω
Small wide area
2400
< 1000 m
< 3000 m
1.5 mm
2
, R < 90 Ω
5
6
8
9
7
GND
RTS
CTS
Rx
Tx
CAUTION
On first start-up the module must be supplied without any interruptions for at least 72 hours to charge the internal
batteries. Switch the module off with the PS1 button before connecting inputs and outputs.
To meet the electromagnetic immunity requirements:
- use shielded signal cables;
- connect the shield to a preferential instrumentation earth system;
- separate shielded cables from other cables used for power installations (transformers, inverters, motors, etc...).
