Re: question about Channel Archiver

[Thomas Birke <Thomas.Birke@bessy.de>]

huangsong wrote:

> Thanks for reply.
>
> The 'data'command print the correct time.
> My Host is running Linux 9.0, TZ isn't defined. 
> After I defined it, there has no effect for the problem.
>
> Yes, EPICS_TS_MIN_WEST is used to convert the timestamps of the exported data.
> But what will effect the start time?
>  
Since you are running a slightly old version of the ChannelArchiver I 
unfortunately cannot reproduce your problem, but:

The ChannelArchiver uses (and used to utilize) the functions provided by 
the EPICS-Base to do the conversion of timestamps
   * locattime <-> UTC (or whatever EPICS's base-timezone is)
   * and in the older versions even to convert timestamp <-> string

Nevertheless, in your case, it looks like the timestamp you provide on 
the command-line is always taken as  a UTC-timestamp.
This is definitely not the expected behaviour! And I don't have the 
sources of ChannelArchiver 1.10.2 at hand to look/try it.
I just found an old HP-UX-binary of ArchiveExport (version 1.9.2) 
compiled against EPICS-base 3.13.5 and while playing with the 
environment (setting EPICS_TS_MIN_WEST and/or TZ to different values) 
unfortunately does not show the behaviour you observe!
Indeed it behaves well - it uses EPICS_TS_MIN_WEST to parse the 
command-line-arguments and to print the timestamps for the output. So 
the timestamps printed are always in the range of what I specified on 
the command-line. TZ has no influence at all.

EPICS_TS_MIN_WEST=-480
./hp700-1.9.2/ArchiveExport -start '01/06/04 02:00:00' -end '01/06/04 
02:01:00' directory  MDIZ3T5G:current
...
Time    MDIZ3T5G:current [mA]
01/06/2004 01:59:59.144578069   4.882
01/06/2004 02:00:09.147168847   4.860
01/06/2004 02:00:18.947919171   4.840
01/06/2004 02:00:29.101599783   3.639
01/06/2004 02:00:39.189630846   3.475
01/06/2004 02:00:48.956558186   2.622
01/06/2004 02:00:59.000995515   2.352
01/06/2004 02:01:09.201892629   1.838


EPICS_TS_MIN_WEST=-480
./hp700-1.9.2/ArchiveExport -start '01/06/04 02:00:00' -end '01/06/04 
02:01:00' directory  MDIZ3T5G:current
...
Time    MDIZ3T5G:current [mA]
01/06/2004 01:59:59.797524861   -0.152
01/06/2004 02:00:09.696648741   -0.150
01/06/2004 02:00:19.558158965   -0.153
01/06/2004 02:00:29.772687281   -0.152
01/06/2004 02:00:39.739121581   -0.154
01/06/2004 02:00:49.566553625   -0.154
01/06/2004 02:00:59.764922136   -0.154
01/06/2004 02:01:09.797810589   -0.156

So, sorry, no help actually, just a description of how it "should" behave...

Regards,
Thomas

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