VESDA by Xtralis
VESDA VFT-15 Product Guide
www.xtralis.com
57
D.3
RS485 Communications
For VESDA VFT detectors, the RS485 interface allows:
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up to 30 detectors to be connected together in a multidrop RS485 network
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detectors to be connected to a PC via a RS485/RS232 converter
For connecting VFT detectors to a PC loaded with Xtralis VSC or VSM4 software, you will need an RS232 to
RS485 converter (Xtralis recommends the ADAM-4520 RS232/RS485 isolated converter). The requirements
for RS485 cabling and installation are outlined in Section D.4.
To enable RS485 communications, the detectors will require Modbus addresses to be programmed through a
direct RS232 serial connection first. Details of this can be found in Section D.2.
Xtralis VSC and Xtralis VSM4 use the 'Xtralis MODBUS 485' connection type to enable communications via
the detector's RS485 interface.
The following illustration shows typical connections via the RS485 interface.
A. PC with Xtralis VSC
or VSM4
B. RS232 / RS485
converter
C. VFT detectors
Figure D-3: RS485 network and a connection between detectors and PC via a RS232/RS485 converter.