DF channel timing and AT&T/Yahoo McAfee Securitity


Recommended Posts

18 Feb 2009 shutdown DF data collection and installed the "new" AT&T/Yahoo Security Suite by McAfee.

Had the "normal" problems everytime AT&T changes security programs on the 19th and 20th.

After any DF restart of the *.ctl file, data became misaligned, and stayed misaligned from 5 to 13 hrs after a restart. The time misalignment of channel's data fell into 3 groups, depending on the channel's average setting. Channels with no average had anticipated time at 6 minute intervals. Channels with average of 6 readings per 6 minutes, and channels with 24 readings per 6 minutes were offset

0730 20 Feb 09:

Restarted DF on a *.ctl that routinely collects data with logging and export files. Has been mostly reliable for months, with occassional misalignment of logging data points that occur several times in a 24 hour periods.

Timing glitch at 1448 on channels with 6 averages. Next time was 1458.

0554 22 Feb 09:

Restart DF. Timing glitch at 1136 on channels with 6 averages, times 1136, 1136, 1146, 1152, etc.

at 0338 23 Feb 09:

Row 0 times for each group: 0336:01.055, 0334:01.010, and 0334:46.025 on the 23rd of Feb.

0430 23 Feb 09:

Restart DF. Set priority of DF in WinXp to "real time".

0330 24 Feb 09:

All channel times as expected within 0.0x sec.

All this on a 1.9 Ghz machine "reading" a LJ U3. CPU utilization rarely goes over 30%.

AT&T's last security suite was Norton/Symantec.

Link to comment
Share on other sites

Well, I think you have your answer. Remove McAfee. I generally recommend you remove all secondary applications from your data acquisition PC. They are just too unpredictable. Turn off auto-updates too. We have people that run DAQFactory 24x7x365 without a restart, but they have cleaned their machine and only run DAQFactory. Everytime you start IE, or check email, or run some other app, that app likely eats away a little memory and over time you have to reboot. I see this all the time on my development machine, which I hibernate at night so essentially leave on for a month at a time. So, if you want a system to run 24x7 you have to make it a dedicated system.

As for the antivirus, you have to understand that by design, an antivirus tool has to look at every piece of data being written to disk. Needless to say, this includes files written by DAQFactory. The newer ones I believe also constantly scan memory. I'd bet if I ran DAQFactory on your machine inside of a debugger (which would show what DLLs load), we'd see that a bunch of McAfee stuff gets loaded with DAQFactory. These act like hooks in DAQFactory, and can drag it down.

If your computer is behind a firewall or router (preferably alone behind it), and you only run DAQFactory there is absolutely no reason for antivirus. There are only two ways you can get a virus: through email/browser downloads and through holes in the OS. If you only run DAQFactory you aren't running email or browser, so the first goes away. If you are alone behind a router or firewall, then holes in the OS can't be compromised because the system is invisible to all other systems.

CPU utilization unfortunately is not a good indicator of what is happening, any more than the memory reported in task manager is a good indication of the actual memory being used (though its a start).

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.