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S:\Hp8960\E1962B CDMA 2000\Pi Release\Reference Guide\Chapters\cdma2000_gen_block_diagram.fm
Block Diagram
Host Processor Module
The Host Processor module is responsible for a variety of tasks within the overall test set architecture. These
tasks include:
•
control of the manual user interface (MUI)
•
executing commands and processing data received from the LAN interface
•
executing commands and processing data received from the GPIB interface
•
controlling hard disk access
•
control of all RF and audio hardware modules
•
routing measurement results received form the Digital Signal Processing and Protocol Processor modules to the
appropriate output device (display, GPIB, LAN, serial, etc.)
Voltmeter/Counter
Voltmeter
The voltmeter is primarily used to measure external DC & AC voltages. A secondary purpose is to
measure internal voltages for instrument self-diagnostics.
The external voltmeter is capable of measuring DC voltages up to + 50 VDC and AC voltages up to 50 V peak.
A true RMS detector is used for measuring AC voltages. For internal measurements, a switch routes the
diagnostic MUX output to the Voltmeter 1 path.
Frequency Counter
The Frequency Counter is used to measure external frequencies from the front panel
Audio IN, High or Low BNC connectors, and to measure internal signals for diagnostics. The external input
can receive a signal between 20 Hz and 50 MHz, with a level from 25 mV to 8 V rms.
The counter circuit is based on the METRON IC. This IC contains a reciprocal counter. A reciprocal counter
functions by counting the input signal and a reference signal simultaneously during a selected gate period. At
the end of this period, the counting is stopped and the values of the signal and reference counters are read.
The ratio of these values is used to calculate the input signal frequency.
Audio Section
Audio Analysis Path
Externally applied audio signals can be analyzed through the test set’s DSP module
for such characteristics as AC level, SINAD, or distortion.
The audio signal to be analyzed is input to the test set using the front panel Audio IN High/Low connectors.
The signal is then routed to the Analog To Digital Converter module’s measurement sampler for analysis by
the DSP module.
The Audio In connector accepts signals from 20 Hz to 15 KHz, at input levels from 10 mV to 20 V peak.
