User guide

System Hardware
4.8.3.1 Power supply connections
The BSD-321 is intended for use with 24VDC power supplies. It may
be used in single or dual earth systems.
29
30
31
32
BSD-321
+24V
0V
DC power supply
+24 in
0V in
IE
PE
BSD-321 power,
Single earth system
29
30
31
32
BSD-321
+24V
0V
DC power supply
+24 in
0V in
IE
PE
BSD-321 power,
Dual earth system
System IE
System PE
4.8.3.2 Obtaining RS-485 using the BSD-321 RS-422 connections
RS-485 is obtained by connecting the BSD-321 RS-422 ports in
RS-485 mode. This is done by connecting the A and the X signal
together, and the B and the Y signal. The resulting RS-485 signal
names will the be A and B.
System Description, AutroSafe Integrated Fire & Gas Detection System, 116-P-ASAFE-IFG/XE Rev. B, 2005-10-27,
Autronica Fire and Security AS
Page 33