Loss of time in waveform chart

[delpitik]

I read a measures of 6 TC to field point every senconds and then I view this in a chart whit history data length of 12 hours.
My X axis is a time in data/hour format but after 2 days the chart has loss 8 minute why?
The problem is field point comunication or software?

[kokkie_d]

I would think that your system is controlled by a PC and its internal clock? If so then the PC is the problem and you might want a little program to keep your pc synchronised (free to be found online).

Hope this helps

[delpitik]

My PC is the time server for field point to ethernet.
But is ok ,because at the start the time is right and after 2 days in labview graph the time is incorrect but in field point explorer is correct.....

[AlessioD]

delpitik,
you are using LabVIEW to acquire data coming from FieldPoint and probably you are not accounting for unevenly spaced data in time. here is an example that shows how to correctly chart timestamped data coming from fieldpoint that are not coming in at a constant rate.

http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=B45EACE3EC2156A4E034080020E74861&p_node=174403

Hope this helps,
regards
AlessioD
National Instruments