SRS Labs SR850 - Manual (Page 22)

2-10
Displays and Traces
With a TTL reference signal, the slope needs to be
set to either rising or falling edge.
The signal vector on the polar graph will not rotate
since the phase is a constant. The actual phase
depends upon the phase difference between the
function output and the sync output from the
generator.
The external reference frequency (as measured by
the lock-in) is displayed at the bottom of the
screen. The reference mode is shown as Ext+ for
external TTL rising edge. The LOCK indicator
should be on (successfully locked to the external
reference).
Display the Display and Scale menu.
Change the screen to dual display mode again.
Display the Trace and Scan menu.
Trace 3 is defined as R and is displayed on the top
graph. Let's change the definition of trace 3 to
something else.
Traces are defined as A•B/C. The quantities A, B,
and C are selected from the various quantities
measured by the lock-in.
Trace 3 has now been redefined to be X. The top
graph now displays X. The trace definition is
shown at the upper left of each graph.
Traces may be defined to be ratios and products
of 2 or 3 quantities.
Trace 3 is now defined as X/R and is equal to
cos
θ,
independent of the signal amplitude. The
traces can be defined to display the most useful
quantities for a given experiment. Trace data may
be stored in the data buffers. Scans and chart
graphs will be discussed in a later example.
Change the reference phase shift to check that
trace 3 displays cos
θ
.
Automatically adjust the measured phase shift to
zero. The top display should show cos0° or 1.
Highlight the phase shift.
Press <Ref. Slope> to select Rising Edge.
10. Press [DISPLAY/SCALE]
Press <Format> to select Up/Down.
11. Press [TRACE/SCAN]
Press <1 / 2 / 3 / 4> to select trace 3.
Press the second softkey, next to the trace
definition, to highlight the R.
Use the knob to change the A parameter from
R to X.
Press the second softkey to highlight the
denominator (C) of the trace definition.
Use the knob to change the C parameter from
1 to R.
12. Press [REF/PHASE]
Press [AUTO PHASE]
Press <deg.>