Experimental Physics and
Industrial Control System

Dehong Zhang <[email protected]> · Mon, 05 Jan 2009 10:20:12 -0600

Hi Tom, Happy New Year!

Thank you very much for your advice.  The return value of the "time" command
seems to indicate that my vxWorks clock is off by 6 hours, will talk to the expert
doing this.

Best regards,
Dehong

----- Original Message -----
From: "Thompson, David H." <[email protected]>
Date: Sunday, January 4, 2009 1:53 pm
Subject: RE: Timezone setting with R3.14.10
To: Dehong Zhang <[email protected]>, [email protected]

> How does the local vxWorks clock get set?
>  
> Epics time is # seconds since 1/1/1990 00:00:00 UTC and the basic 
> vxWorks clock is from 1/1/70 00:00:00 UTC.  It should be easy to look 
> at the return value from time() and the seconds field in a running 
> record and see if the # seconds there is UTC or CST by just taking 
> that number modulo the # seconds in a day.
>  
>  
> The timezone fields are only used for local time display purposes and 
> would not impact what a camonitor would report.
>  
> This is what we do:
> putenv("EPICS_TS_MIN_WEST=300")
> 
> # New DST changes for 2007 Eastern Time Zone US
> 
> putenv("EPICS_TIMEZONE=EUS::300:031102:110402")
> 
> We also set the local vxWorks clock from NTP at the start, this makes 
> the DST calculation go correctly.  The calls can be made from the 
> startup script.
>  
> 
>  
> ________________________________
> 
> From: [email protected] on behalf of Dehong Zhang
> Sent: Tue 12/30/2008 11:36 AM
> To: [email protected]
> Subject: Timezone setting with R3.14.10
> 
> 
> 
> Hi Everybody, Happy New Year!
> 
> Recently we upgraded to 3.14.10 (on vxWorks 6.1).  We are trying to 
> use the time
> from the local vxWorks system, instead of the EPICS time/boot server.  
> So we do
> NTPTime_Shutdown
> immediately before iocInit.
> 
> On the vxWorks console, we can see that the NTP thread is indeed off:
> 
> generalTimeReport 1
> Backwards time errors prevented 0 times.
> 
> Current Time Providers:
>     "NTP", priority = 100
>         Current Time not available
>     "OS Clock", priority = 999
>         Current Time is 2008-12-30 10:31:48.890000.
> 
> Event Time Providers:
>         No Providers registered.
> value = 0 = 0x0
> 
> Please note: the OS Clock does show the correct local time (US CST).
> 
> But on a host machine, if we start a monitor process like "camonitor ..."
> we always get the time off by 6 hours.  It seems EPICS takes the CST time
> as the GMT time, then convert it back to CST.
> 
> We tried both
> putenv("TIMEZONE=...
> putenv("EPICS_TIMEZONE=
> 
> They did not help.
> 
> Please advice.
> 
> Thanks much and best regards,
> Dehong
> 
> 
> 
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System