Teledyne 1220 - Multipoint flammable gas and vapor detection system - Manual (Page 30)

4 Operation Model 1220
4-2 Teledyne Analytical Instruments
4.2 Control Unit Operation
4.2.1 System Power Switch and LED
The power to the entire 1220 system is controlled by the System
Power Switch.
The green System Power LED indicates system power status (ON/
OFF).
4.2.2 Audible Alarm Switch and Bypass LED
The Audible Alarm Switch overrides the audible alarm when in the
Bypass position. The red Bypass LED lights when the audible alarm is
bypassed.
4.2.3 Fuses
For fuse replacement/installation, see section 3.3.1 and 3.4.3
4.2.4 RS485 Port
NOTE: This feature is not presently supported--contact the factory for
application assistance.
An RS485 port is provided at the 9-pin D-sub connector. The RS485
port is connected internally to all of the Channel Modules in the system.
Control Unit - Front View