Stanford Research Systems SR865A, Operation Manual

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Chapter 4 Programming 129
SR865A DSP Lock-in Amplifier
Example
SCNAMPATTN 1 Set the scan amplitude attenuator mode to fixed
SCNAMPATTN?
Returns the mode for amplitude output attenuators
SCNDCATTN(?) {i}
The
SCNDCATTN i
command sets the operating mode for the output attenuators when
scanning dc level to automatic (i=0) or fixed (i=1).
Normally, the sine out dc level hardware will automatically switch one or more balanced
attenuators into the dc level signal path to optimize performace for the commanded level.
During scans, however, it can be helpful to force the attenuators to remain in a fixed
configuration, inhibiting the relay switching that would otherwise introduce transients in
the sine output.
Example
SCNDCATTN 1 Set the scan dc level attenuator mode to fixed
SCNDCATTN?
Returns the mode for dc level output attenuators
SCNINRVL(?) {i}
The SCNINRVL i command sets the parameter update interval according to the table
below.
i Update Interval i Update interval
0 8 ms 9 9.375 s
1 16 ms 10 28.12 s
2 31 ms 11 56.25 s
3 78 ms 12 112.5 s
4 155 ms 13 5 m 37 s
5 469 ms 14 11 m 15 s
6 938 ms 15 22 m 30 s
7 1.875 s 16 45 m 00 s
8 4.688 s
The parameter update interval is the approximate time spent at each scan step along the
way during a scan.
Example
SCNINRVL 8 Set parameter update interval to 4.688 s
SCNINRVL?
Returns parameter update interval index i
SCNENBL(?) { OFF | ON | i }
The
SCNENBL i
command turns scanning off (i=0) or on (i=1). This sets the scan
parameter to its begin value but does not start a scan.
Example
SCNENBL ON Turn scanning on