Tektronix 070-8811-08 - Manual (Page 102)

Appendix B: Error/Warning Messages
764 Digital Audio Monitor User Manual 87
NOT PRESENT (Option 01 only)
Location: In-bar.
The NOT PRESENT flag indicates that, although video input is
detected, there is no active audio on the corresponding channel (no
channel ID is detected).
PARITY
Location: In-bar.
The incoming subframe does not have even parity as specified by
the applicable digital audio standards. The data sample is unreliable
and is ignored. The meter bars and phase pattern treat the sample as
a zero sample.
The PARITY indicator persists for the “CLIP/MUTE Hold Time,”
set through the Level Meters submenu. When a Session is running,
the instrument counts parity errors and displays the current total on
the Session display.
SYNC ERR
Location: Audio View, below the affected meter pair (1–2 or 3–4).
Either the input is out of synchronization with the REFERENCE
input signal by at least 25% of the digital audio sample frame, or the
input-to-reference timing is constantly changing due to mismatched
sampling frequencies.
When the 764 is not locked to an incoming signal on the REF-
ERENCE input, the presence of this flag below the channel 3–4
meter bars indicates that the two inputs (CH 1–2 and CH 3–4) are
out of sync with each other. Again, the signals can be mistimed by a
quarter-frame or more, or be “sliding” relative to one another due to
a sample frequency mismatch.