Re: GPIB - asyn - streamdevice

[Eric Norum <norume@aps.anl.gov>]

On Nov 3, 2008, at 3:39 AM, Dirk Zimoch wrote:

> Hi Zen,
> .

> .
> .
> ASCII is usually a quite inefficient encoding for huge waveforms.  
> Often devices offer a "raw" format, (e.g. 2 byte integer). This  
> format is not terminated because raw input may consist of CR LF  
> bytes. However, it has a fixed input length. Often is is prefixed by  
> a header that defines the input length. Unfortunately StreamDevice  
> cannot interpret this header. (This would be something for a asyn  
> interpose layer, I guess). But you can easily calculate the size  
> yourself. If the header looks like this "#800001000" the total input  
> size is 1010 (10+2*500). And you can use a format like this:

This format is an IEEE-488.2 standard.  For an example of reading this  
see the readArbitraryBlockProgramData() function in the ASYN devGpib  
support (modules/soft/asyn/asyn/devGpib/devSupportGpib.c).
For an example of this function's use see the Tektronix TDS3000/5000  
support (modules/instrument/tds3000/TDS3000/src/devTDS.c).
--
Eric Norum <norume@aps.anl.gov>
Advanced Photon Source
Argonne National Laboratory
(630) 252-4793