Dräger Babylog 8000SC, Technical & Service Manual, Page: 44 / 155

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Dräger Medical AG & Co. KGaA 6173.3
Function description Babylog 8000
10.6 Monitoring PCB
The Monitoring PCB measures and monitors all measurement and status signals. The Monitoring PCB
compares these signals with the signals from the CPU 68000. If an error occurs, the Monitoring PCB
switches off the valves, activates the audible alarm generator, and resets the CPU PCB.
A Z80 microprocessor (minimum system) controls the Monitoring PCB. The Monitoring PCB
communicates with the CPU 68000 via a bus interface.
10.6.1 Measurement of Analog Signals
O
2
concentration
Potentiometers (O
2
, Vinsp, T
I
, T
E
, P
insp
, PEEP/CPAP)
Pressure P
insp
System temperature
Supply voltages (potentiometer reference, rechargeable battery, GNDA, GND reference, 27 V)
Valve voltage
10.6.2 Measurement of Digital Inputs
STATUS CPU 68000 (reset)
STATUS flow (reset)
STATUS I/O (printed circuit board is available)
STATUS valves (current and drive monitoring on the Pneumatics Analog PCB)
Powerfail
Position of power switch
10.6.3 Measurement of Digital Outputs
Alarm LEDs (2 LEDs on the Display PCB)
Flow test 1 and 2 (for Flow PCB)
Switching on of valve relays K1 and K2 (voltage supply to valves and PEEP/PIP valve on the
Pneumatics Control PCB)
CPU PCB reset
7-segment status display for error messages
Standby audible alarm generator
Loudspeaker monitoring via microphone
Battery charging and testing circuit
Test of the supply vo5 V, +15 V, –15 V (Display PCB)