Experimental Physics and
Industrial Control System

Ralph Lange <[email protected]> · Tue, 26 Jul 2005 17:05:30 +0200

Kay-Uwe Kasemir wrote:

On Jul 26, 2005, at 05:49, Ralph Lange wrote:

1. Learning the native type of data is part of the DA interface. The

DA interface is purely about data and does not have any notion of

network transport. An application may access things within a library

or through shared memory using DA without any network involved.

The application should see a data interface
that allows random access:
List the properties,
learn that the 5th property is the "value",
typed as some sort of number, then fetch it as a double.
Ask for the "units" property as a string, ...

I don't see your point here, as all this is true for Data Access

(assuming that the surveyor yields something comprehensive and /not/

just empty objects):

- The traverse methods will list properties and types (surveyor)

- The find method will fetch a property by name (the viewer will convert

it to the format of your local storage)

The knowledge that something is "the 5th" property in a catalog does not

hold any information, as all access is only by property name/id. Of

course your app may count and number properties any way it wants. (Data

Access does not preclude you from counting properties. ;-)

Ralph

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System