I'm setting up a small system to monitor things like line voltage and temperature.
It uses a serial connection to a UPS box to get the line voltage. The quirk is that the drift changes when I run the monitoring program. It changes more if I poll faster. It changed by 20 ppm when I was polling with a 10 ms delay and it's more than 80 ppm and still climbing when I reduced the delay to 1 ms. I let it run for a few days in the 20 ppm mode. The drift was stable, just like it was before I turned on the monitoring code. I can see it track the daily temperature changes. The system is a VIA C7 CPU with a VT3314 chipset running a 2.6.25 kernel. The kernel sources are stock but the configuration options are my own. Has anybody seen anything like this? Any suggestions on where I should look for more info and/or to track this down? -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
