Agilent Technologies 35670-90066 manual A10 Rear Panel, Dac

Agilent 35670A	Circuit Descriptions
	A10 Rear Panel

	A10 Rear Panel
	The A10 Rear Panel assembly contains the BNC connectors for the external trigger
	input, tachometer input, and source output. The Rear Panel assembly also contains
	DIN, GPIB, serial, and parallel interface connectors. In addition, the Rear Panel
	assembly provides the fan control for the A90 Fan assembly.
GPIB Controller and	Allow the analyzer to communicate with devices such as plotters, printers, or a host computer
Buffers	via an GPIB cable. These circuits handle all GPIB functions for the analyzer.
Parallel Port Controller	Allow the analyzer to send data to printers with Centronics interfaces.
and Buffers
IIC Processor	Provides the interface from the DIN keyboard connector to the A7 CPU assembly. The IIC
	Interface also decodes the control lines for the DAC.
DAC	Sets the tachometer trigger level. The A7 CPU assembly sends the control signals to the Rear
	Panel assembly over the IIC bus. The IIC Processor decodes the control signals.

Tachometer Comparator Compares the input signal from the Tachometer BNC connector with the trigger level set by the DAC. The output of the comparator changes TTL levels when the input signal crosses the trigger level.

External Trigger Buffer Buffers the external trigger signal.

Fan Control	Provides the A90 Fan assembly with a voltage that controls the fan speed. A temperature
	sensor provides a control signal that changes with the analyzer’s internal temperature. When
	the temperature increases, Fan Control increases the fan speed. When the temperature
	decreases, Fan Control decreases the fan speed. Control lines from the A7 CPU assembly can
	also set the fan speed to high or turn the fan off.
Serial Driver	Drives the serial data lines to and from devices connected to the Serial Port. The serial port is
	only available using Instrument Basic.

8-33