6
3.2 User Interface
3.2.1 Operating Knob
The Operating Knob is a combined ON/OFF
switch and vacuum selector, located at the bot-
tom of the User Interface.
The LSU is switched ON by turning the
Operating Knob to the required setting. Each set-
ting indicates the maximum achievable vacuum
level for the selected position (80, 120, 200, 350,
500+ mmHg).The free air flow value changes
along with the increasing vacuum settings
(see section 11.4 for details).The LSU is switched
OFF by resetting the Operating Knob to "0".
Even if the Operating Knob is in “0” position,
voltage is present on some of the internal circuit-
ry, when the LSU is connected to mains.To fully
remove power, pull out the Power Cord.
3.2.2 Indicators
3.2.2.1 Power ON Indicator
This green LED has 3 modes:
- It is lit continuously while the LSU is
switched ON.
- It flashes rapidly (approx. twice per second)
during the Device Test.
- It flashes slowly (approx. once per second)
while the Automatic Power-save Function is
activated, if the Device Test is interrupted or
when the battery is discharged.
3.2.2.2 External Power Indicator
This green LED is continuously lit
while external AC or DC power is connected.
3.2.2.3 Failure Mode Indicator
The red LED is lit when a possible
malfunction of the LSU has been
detected. If lit, turn the LSU OFF, and then ON
again to check if the indication disappears.
Provided that the indication does not occur
again the LSU can be operated. If the Indicator
continues to lit after three OFF/ON cycles and
after replacing the battery with a fully charged
battery, discontinue use and return the LSU for
service. (See section 9).
Power ON Indicator
External Power Indicator
Failure Mode Indicator
TEST-Button
Vacuum Indicator
Battery Status Indicator
Operating Knob
