Stanford Research Systems SR810 Manual page 93

Remote Programming
STRD
After using FAST1 or FAST 2 to turn on fast data transfer, use the STRD
command to start the data storage. STRD starts data storage after a
delay of 0.5 sec. This delay allows the controlling interface to place itself
in the read mode before the first data points are transmitted. Do not use
the STRT command to start the scan. See the programming examples
at the end of this section.
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