Sure, this helps.
I modified as suggested and it works. Thanks a lot.
BTW, it wound be nice to have in the Record Reference Wiki an examples.
Like in the "MySQL reference manual", where for every command people
post their examples, sometimes not trivial examples. Later people could
use them instead of starting from scratch.
Probably, a similar thing exists already, but I don't know the place.
Regards,
Nerses
On 02/14/2012 01:34 PM, Andrew Johnson wrote:
Hi Nerses,
On 2012-02-14 Nerses Gevorgyan wrote:
I'm trying to put into waveform record an array of STRINGs.
As I understood from waveform code and manual the VAL field is
a void pointer which should be supplied by user.
Sorry, if that's what the record reference manual says it's wrong.
The prec->val field is never actually used inside the record source code.
When you the access the VAL field of a waveform record through CA or a
database link, the data is actually fetched from the prec->bptr field, which
gets initialized in the first pass of record initialization to a point to a
buffer that holds NELM values of the type FTVL. Device support should copy
its data into this buffer, never modify the prec->bptr field itself.
For a case of array of STRINGs it could have different organizations. Like:
1) elements delimited by NULLes
aaa\0bbbbbb\0cc\0...
2) each element of array has a fixed length chars and the names then
padded with NULL-es like below
aaa\0\0\0\0\0\0\0bbbbbb\0\0\0\0cc\0\0\0\0\0\0\0\0
When FTVL=STRING the array elements are all MAX_STRING_SIZE=40 characters
long, thus when NELM=2 the buffer is 80 bytes long and the second string
element starts at offset 40 into the buffer.
Hope this helps,
- Andrew
- Replies:
- Re: How to get array of strings from waveform record? Andrew Johnson
- References:
- How to get array of strings from waveform record? Nerses Gevorgyan
- Re: How to get array of strings from waveform record? Andrew Johnson
- Navigate by Date:
- Prev:
epics-arduino Emmanuel Mayssat
- Next:
Re: epics-arduino Marty Smith
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
<2012>
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
Re: How to get array of strings from waveform record? Benjamin Franksen
- Next:
Re: How to get array of strings from waveform record? Andrew Johnson
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
<2012>
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
|