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<== Date ==> | <== Thread ==> |
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Subject: | newbie question : one shot measurement |
From: | Jérôme Poincheval via Tech-talk <tech-talk at aps.anl.gov> |
To: | "tech-talk at -aps.anl.gov" <tech-talk at aps.anl.gov> |
Date: | Thu, 24 Mar 2022 16:54:28 +0100 |
Hi tech-talk,
I am new to epics, and using it to read data from a keithley scpi multimeter.
I want to get one shot readings, not periodic ones. So, to trigger an 'on-demand' measurement, I write a value to the .PROC field of my passive record to trigger processing, then read the value.
This works well, but I wonder if there is a 'read-data-now'
function in epics which I have overlooked ?
##### excerpt from .proto file :
# one shot measurement
measure {
ExtraInput = Ignore;
out ":measure:\$1?";
in "%f";
}
##### excerpt from .db file :
# read dc
voltage, triggered by putting a value to measure_v_dc.PROC
record (ai, "$(PORT):measure_v_dc") {
field (DESC, "voltage/dc one shot measurement")
field (DTYP, "stream")
field (INP, "@scpi_keithley_2000.proto
measure(voltage:dc) $(PORT)")
field (SCAN, "Passive")
}
-- Jérôme Poincheval poincheval at lpccaen.in2p3.fr tel:02.31.45.29.87 LPC Caen http://www.lpc-caen.in2p3.fr