Honeywell GX-Series User Manual

GX-Series Control Panel Installation and Setup Guide
2-9
RS485 Data Communication Bus (AB Lines)
Communication between the GX-Series control panels and the modules attached to the system takes place
on the AB lines. The communication protocol is RS485 format. The control panel constantly monitors the
modules attached to it. A break in the communication from any of the modules generates a module tamper
alarm.
RS485 Wiring Configurations
The system must be wired in a daisy-chain configuration. That is the A line from the previous module is
connected to the A terminal of the current module and then on to the A line of the next module. The RS485
(AB) line must have a 680 • resistor installed across the A and B terminals of the last module on the line. If
two lines are connected, both ends must be terminated with 680 • resistors and the appropriate link (LK3 or
LK5) removed.
GX-Series
Control
Panel
680 Ω
Fit LK3/LK5 on PCB
A
B
AB
680 Ω EOL
A
B
GX-008-V2
Keypad
OR
Module
Figure 2-8. Daisy Chain Configuration
Each AB line can run in two directions from the control panel.
• Remove link LK3 (RS485 line 1) or link LK5 (RS485 line 2).
• Run two lines from the A and B terminals of the line.
• Terminate both Ends of Line (EOL) with a 680 ohm resistor.
NOTE: It is permissible to have different configurations on each line. For example, line 1 – Daisy chain; line 2 -
twin AB daisy chain.
A
B
A
B
GX-Series
Control
Panel
680 Ω EOL
680 Ω EOL
A
B
Remove
LK3/LK5
Keypad
OR
Module
Keypad
OR
Module
GX-009-V2
Figure 2-9. Twin AB Line Daisy-Chain configuration
RS485 Wiring Recommendations
To ensure that the system communicates at the maximum level of efficiency, the following recommendations
must be adhered to:

Honeywell GX-Series Specifications

General

Brand	Honeywell
Model	GX-Series
Category	Control Panel
Language	English