User manual

Audio Generator
AM700 Audio Measurement Set User Manual
4-31
Variable Freq. Edit this field to specify the clock frequency when in Variable
Frequency mode.
Offset. Edit this field to adjust the output clock signal frequency offset (in parts per
million) with respect to the internal audio sample rate or the external reference
input.
Phase Offset. Edit this field to change the phase (in unit intervals) of the digital
audio output clock with respect to the reference output clock.
Main Output Interface Amplitude. Use the Main Output Interface Amplitude section of
the Advanced Digital Interface screen to adjust the voltage on the XLR or the BNC
output connectors. This is useful when you want to determine the lowest input
voltage at which an instrument can lock to an input signal. The ratio of BNC-
to-XLR connector output voltage is always 1:5. Selecting one field editor and
changing the voltage automatically updates the voltage value shown in the other
field editor in this ratio.
Long Cable Simulator. Use the Long Cable Simulator check box to switch a
low-pass filter circuit in and out of the XLR digital audio output. The purpose of
this is to distort the signal in such a way that it simulates the signal that is present on
a cable roughly 100 meters long. This can be used, for example, in acceptance
testing to determine whether an instrument is able to lock to a signal received from
a long cable.