User Manual - TRS-RenTelco

Option SD/HD Detailed Measurement Information
Sync
This measurement is used to check synchronization signal timing and amplitude,
including the relative position of the start and end of active video (interpreted by
looking at front and back porch times).
Signal Source
You can use the matrix signal, or you can use a signal with signal amplitude
greater than 7.5% at the beginning and end of active video in order to measure
front porch and back porch times.
Interpreting Results
The amplitudes are measured relative to back porch.
Selecting either 1080 or 720 formats will display the tri-level sync results.
Selecting either 480 or 576 will display the bi-level sync results.
How Results are
Calculated
The amplitudes are measured relative to back porch.
The times are taken as the time between half amplitudes of adjacent transitions.
For example, “Neg. Sync Width” is the measured time between the half
amplitude of the falling or leading edge of negative sync and the half amplitude
of the rising or trailing edge of negative sync.
In the absence of sufficiently large (greater than 7.5%) video signal, the width of
front porch and back porch may not be found. In this case, the measurement of
the respective porch widths will not be valid.
The Sync relative to reference value is calculated as follows:
Result = (measured value − reference value)
VM5000 Automatic Video Measurement Set User Manual 3-37