Circutor CVM-A1500 - 6�- Integrated Communications; 6�1�- Connections

6�- INTEGRATED COMMUNICATIONS
The CVM-A devices have one RS-485 communications port.
The device has as standard two communications protocols: MODBUS RTU ® and BACnet.
The protocol and conguration parameters are selected on the setup menu. (“5.7.19.- INTE-
GRATED COMMUNICATIONS.”).
The device is factory congured with the MODBUS protocol.
6.1.- CONNECTIONS
The RS-485 cable should be wired with a twisted pair cable with mesh shield (minimum 3
wires), with a maximum distance between the CVM-A and the master device of 1200 metres.
A maximum of 32 CVM-A devices can be connected to this bus.
Use an intelligent converter to establish communications with the master device.
B ( - )
RS-232 / USB / Ethernet / Profibus ...
PC
B ( - )
A ( + )
RS-485
S
A(+) B(-) S A(+) B(-) S
RS-485
RS-232
USB
Ethernet
Profibus
...
Figure 325: RS-485 Connection diagram�
227
Instruction Manual
CVM-A1000 - CVM-A1500