Operation Manual

LX90xx system Version 4.0 February 2014
Page 21 of 151
4.5.4 USB-D or Analog unit wiring
4.5.5 Connecting vario unit
Vario unit is connected to main unit through RS485 bus. SC cable is used for external switch,
for switching between climb and cruise mode. In case that SC is connected to flaps switch,
VP (vario priority) is connected to switch on stick. Inputs IN1..4 are used to connect to gear
switch, airbrakes, etc...
4.6 Installation of Options
All options (Rear Seat Device, Remote Control, Compass Module & secondary vario
indicators) are prepared to be connected to the RS485 system bus by use of RS485 splitting
units. Installation of any option is plug-and-play and therefore requires only mechanical
installation work. The main display unit also powers all devices connected to the bus. An
automatic fuse built into the main display unit prevents damage to the digital unit should a
short circuit in the wiring or in some attached device occurs.