Real Time Clock

How does QNX stay in sync with the real-time clock? Does it only read the
real-time clock at boot?

We have three systems that were reverting the real time clock to specific
times. Most of the problems occurred at customer sites, but the problem
occurred here at least twice. The problem may be related to writing data to
USB datakeys. Our application should only be setting the real time clock
when the user changes the date or time.

Serial 2 always went back 7 times to between 01:06 and 01:51 on 10/28.
Serial 6 always went back 4 times to between 19:02 and 19:47 on 10/30.
Serial 11 always went back 11 times to between 01:10 and 01:50 on 10/30.

We’re running QNX 6.3.0 SP1 on Ampro CoreModule 600’s.

Thanks, Dennis

Dennis Miller <dmiller@nospamminnetronix.com> wrote:

How does QNX stay in sync with the real-time clock? Does it only read the
real-time clock at boot?

The OS only reads the RTC at boot time, and doesn’t set it. QNX does not
try to stay in sync with the RTC. The rtc utility can read or set the RTC
if run. If you run an NTP server or client, it may talk to the RTC.

-David

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