Agilent Technologies 1670G Series Service Manual page 204

Theory of Operation
The Oscilloscope Board
DC Cal The DC Cal output, a rear panel signal, is used for self-calibration. It is one
output from the 16-channel DAC.
Digital Interface The Digital Interface provides control and interface between the
system control and digital functions in the acquisition circuitry.
Analog Interface The Analog Interface provides control of analog functions in the
acquisition circuitry. It is primarily a 16-channel DAC with an accurate reference and
filters on the outputs. It controls channel offsets and trigger levels, and provides the DC
Cal output.
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