[time-nuts] Timelab, two SR620s and losing samples
attila at kinali.ch
Sun Jan 17 04:46:51 EST 2016
On Sat, 16 Jan 2016 13:33:54 -0800
"John Miles" <john at miles.io> wrote:
> Agreed with Magnus that there are a lot of possible variables in your setup
> that need to be ruled out.
Yes, too many. And it isn't really helping that I hardly understand what
I am doing.
> Are you using the SR620 driver in TimeLab, or did you find a way to get
> it to emit data continuously via the RS232 port for use with the talk-only
I am using TimeLab and start two acquisitions. That part seems to work
> I've seen occasional instances where a counter has ignored every other
> trigger when used in addressable mode by TimeLab. It's not always readily
> reproducible, but the counter drivers in the current beta at
> http://www.miles.io/timelab/beta.htm seem to be a bit less prone to that
> behavior. If you aren't already using the beta, try that.
Thanks! I'll try that tomorrow.
> It's always safest to use counters in talk-only mode when possible, since
> that rules out any timing problems that might arise in a two-way GPIB or
> serial conversation where each individual reading is requested by the
> software as done by the 5313xA, Philips, DTS2070-series, and SR620 drivers.
> Some of those counters can be used in both talk-only and addressable modes,
> but I don't believe that's true of the SR620, unfortunately. All of the
> programming examples in the SR620 manual work by requesting each reading
Hmm.. I have set TimeLab to do samples every 0.1 seconds, and have an
external trigger with the same interval (SR620 setting ist Ext +/- Time).
Could it be that TimeLab just samples a little slower than the 0.1s,
so that it misses a measurement once in a while and has to wait until
the next trigger arrives?
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