Rs485 Wiring Recommendations - Honeywell Galaxy 3-48C Installation Manual

Galaxy 3 Series Installation Manual
A
680 Ω EOL

RS485 Wiring Recommendations

To ensure that the system communicates at the maximum level of efficiency, the following recommendations
must be adhered to:
1. Each communication line can support 32 devices. The maximum number of devices on each line
are:
2. The system must be wired in a daisy-chain configuration. Spur and star configurations must not
be used as they reduce the immunity to electrical interference.
3. The cable used to connect the RS485 (AB) line must be screened twisted pair (Part No. W002) or
Belden 8723 equivalent.
4. Shielded twisted pair cable, where used, is connected to the earthing pillar on the Galaxy control
panel using the P-clip and nut supplied (refer to Figure 2-10).
The RS485 (AB) line must have a 680 Ω resistor fitted across the A and B terminals of the last
5.
module on the line. If twin lines are connected, both ends must be terminated with 680 Ω resistors and
the appropriate link on the control panel PCB must be removed (refer to figure 2-9).
Keypad/Keyprox
OR
Module
B
Figure 2-9. Twin AB Line Daisy-Chain configuration
Galaxy 3-48
(Line 1 only)
Keypads 8
Keyprox 3
RIO's/SPSU's
4
Output Module
4
RF RIO 4
MAX 4
RS232
1
Telecoms 1
Printer 1
ISDN
1
Ethernet 1
Table 2-5. Communication Devices
RS485 Recommendations
Keypad/Keyprox
OR
Module
Galaxy
Control
Panel A
B
Remove
LK3/LK5
Galaxy 3-144 Galaxy 3-520
(Lines 1-2) (Lines 1-4)
8 per line 8 per line
3 (line 1) 3 (line 1)
4 (line 2) 7(lines 2, 3, 4)
15 (line1)
8 per line
16 (lines 2, 3, 4)
4 per line 4 per line
15 (line 1)
8 per line
16 (lines 2, 3, 4)
4 per line 8 per line
1 (line 1 only) 1 (line 1 only)
1 (line 1 only) 1 (line 1 only)
1 (line 1 only) 1 (line 1 only)
1 (line 1 only) 1 (line 1 only)
1 (line 1 only) 1 (line 1 only)
2-11
A B
680 Ω EOL