Stanford Research Systems DS345, Manual

Page: 25 / 139

Introduction
The following sections describe the operation of the DS345. The first section
describes the basics of setting the function, frequency, amplitude, and offset.
The second section explains sweeps and modulation. The third section ex-
plains storing and recalling setups, running self-test and autocalibration, and
setting the computer interfaces. The fourth and last section describes front
panel editing of arbitrary waveforms.
Power-On
When the power is first applied to the DS345 the unit will display its serial
number and ROM version for about three seconds. The DS345 will then ini-
tiate a series of self-tests of the circuitry and stored data. The test should
take about three seconds and end with the message "TEST PASS". If the
self test fails the DS345 will display an error message indicating the nature of
the problem (see the
TROUBLESHOOTING
section for more details, page 4-
1). The DS345 will attempt to operate normally after a self-test failure, (press-
ing any key will erase the error message).
DS345 OPERATION
SETTING THE FUNCTION
SYNC
FUNCTION
40V max
50
Ω
TTL
NOISE
TRIG'D
FREQ
AMPL
TTL
ECL
OFFST
REL=O
PHASE
ARB
OUTPUTS
The FUNCTION and SYNC BNCs are the DS345's main outputs. Both of
these outputs are fully floating, and their shields may be floated relative to
earth ground by up to ±40V. Both outputs also have a 50
Ω
output impe-
dance. If the outputs are terminated into high impedance instead of 50
Ω
the
signal levels will be twice those programmed (the FUNCTION output may
also show an increase in waveform distortion). The programmed waveform
comes from the FUNCTION output, while the SYNC output generates a TTL
compatible (2.5 V into 50
Ω
) signal that is synchronous with the function out-
put. The SYNC signal is suppressed if the function is set to NOISE or
BURST modulation. If the function is set to ARB the SYNC signal is a 25ns
negative going pulse at the start of each waveform.
2-9