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

Subject: CA and unsigned types
From: "Brian McAllister" <[email protected]>
To: [email protected]
Cc: [email protected]
Date: Tue, 14 Aug 2001 18:41:29 -0400
>>> On 11/12/1996 at 16:55:17 GMT, Jeff Hill wrote:

  > The unsigned integer types used internally in the database do not
  > currently exist in the ca client API. To get around this problem EPICS
  > ioc core informs clients attached to "unsigned int" fields that the
  > native type is "float". This promotion to a larger type guards against
  > the loss of information during type conversions.

  > Johnny Tang at CEBAF has recommended that "unsigned char" and "unsigned
  > short" should map to a 32 bit integer external type (without loss of
  > information). This change is planned for the next release of EPICS.

Is this behaviour actually documented anywhere other than the Tech-Talk
archives ?

I found no mention either in the Record Reference Manual or the App.
Developer's Guide.

Was the effect on large arrays considered ?  In my case, this caused a
waveform record of type USHORT and size 6000 to be unusable.

Is there a plan to implement these types in CA ?

----
Brian McAllister                    Controls Programmer/Beam Physicist
[email protected]                        MIT-Bates Linear Accelerator
(617) 253-9537                                           Middleton, MA



Replies:
Re: CA and unsigned types Brian McAllister
RE: CA and unsigned types Jeff Hill
Re: CA and unsigned types Marty Kraimer

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