16
0004-000067
is not recommended. Note that PVs with scan rates will continue to access the
instrument even if they are not being used. Ensure that all scan rates are disabled
before using a non-CA interface.
Capturing
Before capturing waveforms it is best to configure the instrument as needed (see
Instrument Use Example and the Waveform Process Variables Table). An important PV
to configure is setOpInitCont.
Capture is not designed for use in multiple interfaces. Multiple EPICS interfaces are fine
since they are accessing the same PVs, but automated code and the provided GUIs
have a separate interface, see
Interfaces
above. Accessing waveforms from EPICS and
a non-CA interface simultaneously may cause slower updates or incorrect data
downloads as both interfaces will be attempting to access the same buffers.
Continuous
If setOpInitCont is set to initiate continuously, the instrument will capture waveforms
continuously. In this mode, to capture, set a 1 to OpInitiate, and to stop capturing, set a 1
to OpAbort. While the instrument is running continuously, downloaded waveforms are
only available at 1000 points or less. Larger captures are allowed, but the data is
decimated on read. Continuous initiation will occur as fast as possible, given the
acquisition settings, and it may not be possible to download all waveforms before a new
capture is done. This mode is recommended for Limit and Mask testing.
When running continuously, all waveforms are returned as a single buffer. This allows all
the waveforms to come from the same capture, even though multiple captures may
occur during the time it takes to perform the waveform download. To download the next
waveform capture, process the OpAutoLoad PV. By default, this PV has a fanout to
Input and Calc scaled waveform PVs. Download speed may be increased by removing
any unused channels from the OpAutoLoad fanout. Recommended use is to set a
SCAN on this PV for continual waveform updates during continuous acquisition.
Single
If setOpInitCont is set to single, setting a 1 to OpInitiate will cause a single capture event
followed by the instrument returning to an idle state. Setting the setOpInitCont PV to
capture single waveforms and then setting the .SCAN field on OpInitiate is an alternate
method to capture repeatedly while still allowing full length downloads. This method
may be more desirable to avoid missing data downloads.
