Prism
Operation Manual Issue 2.00
Page 4.3
The sampling frequency LEDs change function when the DSA-1 Signal Generator is
operating. In this state, the 'Fs' LEDs indicate the basic sampling rate of the Signal
Generator, rather than the test input signal.
4.1.7.
fs accuracy display
The fs accuracy indicators at the bottom of the CARRIER panel provide a guide to the
accuracy of the source sampling frequency, in units of ppm (parts-per-million). If none
of these LEDs is lit, then the source fs is within 1000ppm of the standard rate, unless
the 'OTHER' LED is lit. A more precise measurement of sampling frequency accuracy
is available through the menu system.
The right-hand LED is designated 'WRT REF'; if this LED is lit, it indicates that the
DSA-1 has been software-calibrated to an external Ref Sync as described in section
6.9.4. In this case, the accuracy measurement is made assuming that the external Ref
Sync was absolute.
The 'ppm' LEDs are extinguished when the DSA-1 Signal Generator is operating; in
this state, the 'Fs' LEDs are indicating the basic sampling rate of the Signal Generator,
rather than the test input signal.
