Teledyne DA1855A, Operator'S Manual

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Operator’s Manual
922258-00 Rev A 21
When used without ProBus interface, the instrument can be set to factory default settings by
pressing the
V
COMP
and V
DIFF
buttons simultaneously.
Gain X1
Attenuation
÷10
+ Input Coupling Off
– Input Coupling
Off
Bandwidth Limit Full
PVG Voltage +00.000 V
V
COMP
Off
V
DIFF
Off
Input Resistance 1 M
Ω
PVG Mode Roll through zero
Table 4. Factory Default Settings
Sensitivity, Position and Offset
Oscilloscopes are designed to maintain their accuracy for that portion of a signal that is displayed
on-screen. When the signal is large enough to drive the display off-screen, the oscilloscope’s
amplifier must limit the signal in a non-linear mode. Oscilloscopes are designed so that no matter
how the sensitivity, position and offset controls are set, the operator cannot view this distorted
portion of the signal.
When used with a Teledyne LeCroy oscilloscope, the setup is automatic to prevent you from
entering a mode which could result in displaying a distorted signal resulting from overload.
When used with instruments lacking ProBus interface, the instrument’s gain and position controls
should be properly set to avoid displaying the non-linear portion of the DA1855A's output signal
when it is in overdrive. This can be accomplished by observing the following rules:

Turn the oscilloscope input coupling to “OFF” or “GND”, set the oscilloscope position
control to center screen, and do not change it!
If the oscilloscope has an OFFSET control, it
too should be set to zero. Return the oscilloscope’s input coupling to “DC”. Subsequently
adjust the trace position on the oscilloscope screen using the DA1855A PVG and V
DIFF
mode
or V
COMP
input. This assures that the oscilloscope is set to the center of the DA1855A's
dynamic range.

Set the oscilloscope deflection factor to no greater than 100mV/div. The most useful range
for the oscilloscope deflection factors will be between 1mV/div and 100mV/div. Using a
scale factor of 200 mV/Div will allow the nonlinear portion of the DA1855A's output to be
viewed on screen.