SRS Labs SR850 - Manual (Page 192)

6-16
Remote Programming
MATH COMMANDS
The math functions operate on the trace which is graphed in the active display. If the display type is polar,
then the trace most recently displayed (in a bar or chart) will be used. If the active display trace is not stored,
then the math functions will generate an error and have no effect.
The Smooth and Calculator functions CHANGE the stored data. Only the data which is within the time window
of the chart graph is operated upon. If the display type is not a chart, then the most recent horizontal chart
scale and position will be used to determine the region of the trace which is operated upon.
The Fit and Statistics functions do NOT change the stored data. However, these functions only analyze a por-
tion of the data within the time window of the active chart display. If the display type is not a chart, then the
most recent horizontal chart scale and position will be used to determine the time window. The region of inter-
est within the window is determined by the left and right limits. These limits are specified in percent where 0%
is at the left edge, 10% is at the first division from the left, and 100% is at the right edge of the chart graph.
When using the math commands SMTH, FITT, STAT and CALC, the status bytes should be queried after the
command is sent to check if the command generated an error. Common sources of errors are divide by zero
and math overflow. For example, the command line CALC;
❊ ESR?<lf> will perform a calculation and then
return the Standard Event Status Byte when finished. This allows the host program to determine when the
CALC command is finished and whether an error occurred. The Execution Error bit (bit 4) may be checked to
make sure that the CALC command terminated without an error.
SMTH i The SMTH i command smooths the data trace of the active display. The
parameter i selects a smoothing width.
i smoothing width
0 5 points
1 11 points
2 17 points
3 21 points
4 25 points
The SMTH i command may take some time to complete. Use a status
byte query to detect when the smoothing operation is done. If a scan is in
progress, the SMTH command will Pause the scan.
COPR (?) {i} The COPR i command sets or queries the type of math operation select-
ed. The parameter i selects the operation.
i operation
0 +
1 -
2 ❊
3 /
4 sin
5 cos
6 tan
7
√
x
8 x 2
9 log
10 10
x