Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Fri, 09 Nov 2012 14:29:13 +0100

On 08.11.2012 18:02, Eric Norum wrote:

Although not directly related to this thread, an issue I've encountered when attempting to write StreamDevice support for devices with "esoteric" command/reply formats is the inability to provide a custom conversion routine as provided by devGpib.

I went digging through my (very) old e-mail messages and recovered this one proposing an addition to StreamDevice that would allow for user-supplied conversion code.  It's still not quite as general a solution as that provided by the devGpib GPIBCVTIO support but it does allow for message format conversions beyond those provided by StreamDevice.

Perhaps others might find this useful enough that it could be made part of the StreamDevice distribution.

===============================================================================
New format string modifier<function_name>.  For example,
      %<function_name>ld
      %<function_name>f
      %<function_name>lf

Where function_name is the name of a conversion function [...]

Hi Eric

This is quite similar to the checksum functions I already have

implemented, and which use the %<...> format. And if I remember

correctly, this was indeed based on your ideas.

Maybe I can modify this a bit in order to allow general user supplied

functions. Checksums would then be a part of the user function model.

I have to think about this and play a bit.

Escaping to user code is of course always "dangerous". You never know

how much stack the call uses, if it blocks, if it throws exceptions etc.

Dirk

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System