Agilent Technologies Infiniium 90000 A Service Manual page 142

Chapter 7: Theory of Operation
Block-Level Theory
Figure 7-3
Backplane assembly block diagram
Front Panel
The front panel board combines functions from the main keyboard and the Autoprobe interface
board in a single PCA. Refer to the keyboard block diagram in Figure 7-4.
The keyboard links to the scope PC motherboard through a high-speed USB 2.0 interface. The
on-board USB hub serves the PIC microcontroller, the touch screen controller board, and up to
three front panel USB connectors for a customer's peripherals.
A conductive element on the inside of each key shorts a gap on the underlying keyboard circuit
board. The keyboard controller detects this short and sends the proper keypress information to
the system controller on the motherboard.
There are 13 knobs located on the front panel.
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