Circutor CVM-E3-MINI - CVM-E3-MINI-xxx: RS-485 COMMUNICATIONS

7. CVME3MINIxxx : RS485 COMMUNICATIONS
The CVM-E3-MINI-xxx devices have one RS-485 communications port.
The device has as standard two communications protocols: MODBUS RTU ® and BACnet.
The protocol and configuration parameters are selected in the setup menu. (“6.22.- RS-485 COMMUNI
CATIONS Models CVM-E3-MINI-xxx)”).
7.1.- CONNECTIONS
The RS -485 cable must be wired with twisted pair cable with mesh shield (minimum 3 wires), with a
maximum distance between the CVM-E3-MINI and the master device of 1200 metres.
A maximum of 32 CVM-E3-MINI devices can be connected to this bus.
Use an intelligent RS-232 to RS-485 network protocol converter to establish the communications with
the master device.
B(-)
A(+)
S
RS-232 / USB / Ethernet / Profibus ...
PC
RS-485
RS-485
RS-232
USB
Ethernet
Profibus
...
A(+)
B(-)
S
A(+)
B(-)
S
A
B
S
A
B
S
Figure 33: RS-485 Connection diagram.
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CVM-E3-MINI
Instruction Manual