User Guide

Theory Of Operation Teledyne API M100E Analyzer Operation Manual
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11.4.12. I
2
C DATA BUS
I
2
C is a two-wire, clocked, bi-directional, digital serial I/O bus that is used widely in commercial and consumer
electronic systems. A transceiver on the Motherboard converts data and control signals from the PC-104 bus to
I
2
C. The data is then fed to the Keyboard/Display Interface (refer to Section 11.6.1.4) and finally onto the Relay
Board.
An I
2
C data bus is used to communicate data and commands between the CPU, the Keyboard/Display Interface
and the various switches and relays on the Relay Board.
11.4.13. POWER UP CIRCUIT
This circuit monitors the +5V power supply during start-up and sets the Analog outputs, External Digital I/O ports,
and I
2
C circuitry to specific values until the CPU boots and the instrument software can establish control.
04515F DCN6048