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<== Date ==> <== Thread ==>

Subject: Array Information
From: Noboru Yamamoto <noboru.yamamoto@kek.jp>
To: tech-talk@aps.anl.gov
Date: Thu, 05 Aug 1999 16:26:14 +0900
Hi, 

on Page93, chap 7,sect5 of EPICS IOC Application Developer's Guide,it says,
"get_array_info() function  returens the CURRENT number of elements and
the offset of the first value of the
specified array".
In other words,  no_elements which get_array_info() return may be
smaller than the maximu size of this array.

Now, ca library compares requested elements count with privCount field
of channel structure and 
it rejects request when the requested count is larger than privCount.
privCount field is updated only when
channel is (re) connected. i.e. you cannot request loger array data 
than the size of array which get_array_info 
when your channel is connected with the Database.

In our application , the CURRENT number of elements of SubArray records
can vary time to time. 
However,  application program cannot read an array data longer than the
element count which is a element count 
at the time channel is connected. It may loose data and its size cannot
be predictable.

Does anyone encounterd similar problem? Or have you solved this problem?

Ragards,

Noboru Yamaoto
KEKB control Group
KEK, JAPAN


Replies:
RE: Array Information Jeff Hill

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