Unit installation

7
RS485 Data Communication Line (AB Line)
Communication between the Galaxy control panels and the attached modules
takes place on the AB (RS485) communication line. The control panel con-
stantly monitors the modules attached to it. A break in the communication from
any of the modules generates a module tamper alarm.
It is strongly recommended that the system is wired in daisy chain configura-
tion, the recommended maximum length of the AB line is 1 km. For more
information see RS485 Wiring Recommendations below.
Figure 1.6 Daisy-Chain Configuration.
Two AB lines can be run from the control panel. This requires a minor hardware
modification to the control panel PCB, see Figure 1.7 Twin AB Line Daisy-Chain
Configuration.
• Cut resistor R38 on the control panel PCB.
• Run two lines from the A and B terminals.
• Terminate both Ends of Line with a 680 Ω resistor.
Figure 1.7 Twin AB Line Daisy-Chain Configuration.
Note: If a twin AB line configuration is to be used the maximum cable run is 1
km over both runs not 1 km per run.
GALAXY 16+ V2.7
08:58 TUE 22 NOV
1
2
3
A
4
5
6
B
7
8
9
ent
*
0
#
esc
GALAXY 16+ V2.7
08:58 TUE 22 NOV
1
2
3
A
4
5
6
B
7
8
9
ent
*
0
#
esc
A
B
R38 EOL Resistor
(Factory fitted to
control panel PCB)
Galaxy 16/16 plus Control Panel
680 Ω EOL
Resistor
GALAXY 16+ V2.7
08:58 TUE 22 NOV
1
2
3
A
4
5
6
B
7
8
9
ent
*
0
#
esc
GALAXY 16+ V2.7
08:58 TUE 22 NOV
1
2
3
A
4
5
6
B
7
8
9
ent
*
0
#
esc
A
B
R38 EOL Resistor
To be removed
Galaxy 16/16 plus Control Panel
680 Ω EOL
Resistor
GALAXY 16+ V2.7
08:58 TUE 22 NOV
1
2
3
A
4
5
6
B
7
8
9
ent
*
0
#
esc
X
680 Ω EOL
Resistor
RS485 Recommendations