Display Pcb - Dräger 8000 IC Function Description

B-Bit channel, via ports SL0 to SL1 and decoder D2 the displays are read in columns. The
keypad inquiry is also done by means of the multiplexer method via ports R0 to R7. Via ports
SL0 to S11 and decoder D2 the column reading of the keypad is carried out.
3.2.2.2 INOP-LED
The INOP-LED V 34 is triggered by an external signal (watchdog PCB Motherboard) via pin
X1/4.
3.2.2.3 Mains failure LED
The mains failure LED (V26) is externally driven via pins X1/19 and X1/21 (Power Pack PCB).
3.2.2.4 Working LED
The working LED V27 is directly connected to the supply voltage +5 V via the series resistor
R15.
3.2.3

Display PCB

3.2.3.1 Display interface module
The programmable keypad and display interface module 8279 (D1) takes over the display
control on the Display PCB. The output is done with the multiplexer method. Ports A0 to A3
and B0 to B3 are driven as 8-bit channel, via ports SL0 to S11 and a decoder the column
reading of the displays is effected.
3.2.3.1 Use of Display PCB
On units with software version 10.n and 20.n:
- O2
- Skin
- Humidity (Inc. 8000 IC only)
On units with software version 11.n and 21.n:
- O2
- Humidity (Inc. 8000 IC only)
6141.22X Incubator 8000 IC/SC/NC
Function Description
09.99 Page 33 of 49