Philips M3000A, Service Manual

Page: 56 / 293

Temperature and Invasive Blood Pressure (Temp/Press) measurement
40 Introduction to the Instrument
• System CPU communication
• ADC controller and data acquisition
• Wave/numeric processing and filtering
• Pressure/temperature mode detection
Block Diagram of the Temp/Press Software
System CPU Communication
The pressure/temperature measurement section of the CPU contains a serial bi-directional
data communication link to the pressure/temperature modules of the system CPU.
The following data is transmitted to the system CPU:
• Pressure wave
• Temperature numeric
• INOP and error messages
• Status messages
The following data is received from the CPU:
• Control messages
All messages in both directions are secured by checksums.
ADC Controller and Data Acquisition
The data exchange between the A/D converter and the CPU is based on a serial
communication link. The calibration information is periodically refreshed to ensure proper
operation of the converter. The converter generates an interrupt each time new data is
Pressure / Temperature
ADC
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Controller &
Data Acquisition
Wave Processing
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CPU
Communication