Cpu Board; Recorder Board - GE B30 Technical Reference Manual

3.2.3 CPU board

The CPU board contains a processor, memories and all the analog signal processing needed. A
MiniC measuring unit is attached to the board with a flexible PCB. Also supply voltage and an
RS485 serial channel are connected to the CPU board using another flexible PCB.
Analog signals (CO
are fed to the 16-bit A/D converter. The processor controls the A/D converter and calculates
the CO
The processor controls sample flow by adjusting the pump voltage based on the differential
pressure signal. The processor also controls the current of the IR source and keeps it constant.
Calibration data is stored on the EEPROM.

3.2.4 Recorder board

The function of the recorder board is to establish an interface between the recorder unit and
main CPU board in the monitor. The recorder unit related side panel key is connected to the
recorder unit via the recorder board. The recorder unit and the recorder board are connected
together with a special connector. The REC board controls the recorder unit communication
and power.
The REC board is grounded via the recorder unit. If the recorder unit is not installed, the REC
board does not function.
+15
+15 V
V
Dat
Data
a
Figure 6
External Communication
Communication with the main CPU board is established via RS485.
Supply voltage The recorder unit supply voltage, +15V_REC, is provided by the recorder board.
, temperature, absolute and differential pressures and lamp current signals)
2
percentage and respiration rate from this data.
2
Pow
Power
Suppl
er
Supply
y
N
NV
CP
V Memo
Memory
ry
RS48
RS485
Driv
5
Driver
er
REC Board REC Board
Recorder board block diagram
+15V_RE
+15V_REC
Reset Reset
Communicati
Communication
CPU on
U
CT
CTS
S
RE
REC
Ke
C
Key
y
Functional description
C
Record
Recorder
Uni
er
Document no. 2044677-001
Unit
t
8-9