User manual

3152B User Manual Publication No. 980935 Rev. M
4-22 ArbConnection Astronics Test Systems
Arbitrary waveforms. If you do not need exotic waveforms, you can
use one of the built-
in standard wave shapes: Sine, Triangle,
Square, or Ramp. These waveforms can be adjusted for their
frequ
ency and deviation range. On the other hand, you can select
the arbitrary modulating wave opt
ion where you can use any shape,
although
you must load the modulating waveform from an external
application, such as the FM composer in ArbConnection.
Information
on the standard and arbitrary FM functions is given in
Chapter 3. Click on the button next to the required modulating
waveform shape to select it.
Arbitrary FM Parameters –
Allow adjustment of the sample clock
of the modulating waveform. These parameters
are active only
when arbitrary modulating waveform option is selected. The
modulating waveform must be downloaded from an external utility
such as ArbConnection
and the sample clock is programmed from
this location.
To access the required parameter, click on the parameter’
s name
and observe that the LED next to the required parameter turns on.
The value that is associated with the lit LED is displayed on the
digital display. You can use the dial, keyboard, or the [↑] [↓} keys to
adjust the readout to the required setting. Aft
er you modify the
reading, click on the Modify/Execute knob
to update the 3152B with
the new setting.
AM
The AM panel (Figure 4-15) contains parameters for controlling the
amplitude modulation function. To turn the AM function on and
off,
click on the AM button in the State group. The various groups
in the
AM panel are described below.
State
The State button turns on and off the AM function.
AM Parameters
This group contains parameters that allow complete control over the
AM function. These are:
CW Frequency –The CW Frequency
is the frequency of the carrier
waveform.
Baseline –
The Baseline parameter affects the output
characteristics in one of the interrupted run modes (i.e., triggered,
burst). In this case this parameter defines whe
re the signal idles
between triggers. There are two options: CW and DC. The DC
option will set the idle state to a DC level, meaning that in between
triggers, the output resides on a DC
level and generates modulation
when a trigger is accepted. The CW is s
imilar except the signal
idles on the pre-
trigger CW frequency setting, executes the
modulation upon receipt of a legal trigger signal and returns to
continuous CW frequency output.