Chapter 3: System operation 
P/N 3102351-EN • REV 005 • ISS 28DEC18  133 
LED display expander LEDs  
The D16L-VS LED Display Expander provides LED annunciation for up to 16 zones. The 
expander provides two LEDs for each zone. You can install two display expanders in the 
panel. 
LED operation zones 1 through 12 
(Also applies to zones 17 through 28 if the second LED expander is installed.) 
•  LED 1 - Alarm: Red LED flashes 
•  LED 2 - Trouble: Yellow LED flashes 
LED operation zones 13 through 16 
(Also applies to zones 29 through 32, if the second LED expander is installed.) 
•  LED 1 - Bicolor 
Alarm: Red LED flashes 
Non-alarm active: Yellow LED flashes 
•  LED 2 - Trouble: Yellow LED flashes 
For CAN/ULC-S527compliant installations, CO detectors with a CO alarm device type must be 
programmed using zones with bicolor LEDs (zones 13 through 16 (16 zone expander) and 29 
through 32 (32 zone expander)) and the zone type must be set to Supervisory. The panel 
Event Notification must be set to Zone. Using this configuration ensures that when the “CO 
alarm” device type goes active, the panel displays a yellow LED indication instead of a red. 
Figure 54: LED zone designations 
 
2)  LED 2 
(5)  Alarm/non-alarm and trouble zone LEDs