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Log data with lokal realtime timestamps ? or NTC time stamps

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Log data with lokal realtime timestamps ? or NTC time stamps

Postby mnni » Mon Oct 09, 2017 7:40 am

in pico log is it possible to setup data logging with real time timestamps instead of just counting up from zero on the time axis ? ex. use ntc time stamps or just local clock time stamps
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Re: Log data with lokal realtime timestamps ? or NTC time st

Postby Gerry » Mon Oct 09, 2017 11:11 am

Hi mnni,

You can set the time reference for logging to Time-of-day, for the Graph View or SpreadSheet View (by clicking the 'tick' icon to select 'options'), and you can save the Spreadsheet file on exit, which will give you a Real-Time reference column in the prn data file that will be the PC internal clock. Also, unless you are logging data from sensors that can't be used by PicoLog, or you're running out of USB extension ports for sensors connected to your computing platform (remember that you can have up to 20 multi-channel devices controlled by the same time source that PicoLog uses), you shouldn't need an external time source to use as a local-master reference, for a group of sensors.
However, if you are relying on a prn file, with real-time time-stamps for your logging, you can't then have logging which is restarted by PicoLog (automatically creating a new PLWdata file), because prn file saving doesn't work with PLWdata file creation.

The PC clock would be fine for the vast majority of data logging applications, but bear in mind that there is a limited amount of accuracy that can be achieved in using a computing platforms internal clock for synchronization, with typical drift being something like 15mS in 2 hours (which can be an issue if you're doing relatively fast data logging with a PicoLog 1000 series data logger). This is due to the following:
    (a) the limits of the cost/performance compromises in timing system design and component selection.
    (b) the operating systems typical inability to give higher priority to timing functions.
    (c) the frequency with which the operating system synchronizes to NTP servers (which themselves are accuracy restricted by network delays, etc).

To answer the other part of your question, it's not possible to set up Network Time Clock time-stamps as the time reference that PicoLog uses for a data logging session. If you want to log real-time data to more than one file, or you want to use a more accurate time source, then you would need to use our Software Development Kit to create a time stamping, data logging application that can synchronize to the time source, and maintain synchronization.

Regards,

Gerry
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