Stanford Research Systems SR865A, Operation Manual

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Chapter 4 Programming 137
SR865A DSP Lock-in Amplifier
Note that when capturing one sample per trigger, this setting is ignored and one data
sample is always captured as soon as possible after detection of the trigger.
The CAPTURERATE? query returns the actual capture rate in Hz (not the value n).
Example
CAPTURERATE 4 Sets the capture rate to the max rate divided by 2
4
CAPTURERATE?
Returns the actual capture rate in Hz
CAPTURESTART [ ONEshot | CONTinuous | i ] , [ IMMediate | TRIGstart | SAMPpertrig | j ]
The CAPTURESTART i, j command starts data capture for either OneShot (i=0) or
Continiuous (i=1) acquisition. The parameter j selects whether capture starts immediately
(IMMediate start, j=0), is started or stopped by a hardware trigger (TRIGstart, j=1), or
captures one sample per hardware trigger (SAMPpertrig, j=2).
The hardware trigger is a TTL input on the rear panel. The active edge of the trigger is a
falling edge . For hardware triggered start or stop, a triggered start requires using OneShot
acquisition, while a triggered stop required using Continuous acquisition.
Both parameters i and j are required in this command.
This command clears any previously captured data and starts a new capture.
Example
CAPTURESTART ONE, IMM Starts OneShot capture immediately
CAPTURESTART 0, 0
CAPTURESTOP
The CAPTURESTOP command stops data capture in any mode.
If the capture is waiting for a hardware trigger to start, then the capture is aborted and the
trigger will be ignored.
If capture is in progress, then capture is halted. Any data already captured is preserved
and may be read. The remaining space in the current 2kB buffer is filled with zero.
If capture has already ended, the CAPTURESTOP command does nothing.
Example
CAPTURESTOP Stop data capture at the next 2 kB boundary
CAPTURESTAT?
The
CAPTURESTAT?
query returns the data capture state. This is a query only
command.
The returned integer is a 3-bit binary encoded word
Bit Weight Definition
0 1 Capture currently in progress