RE: Read/Write waveforms using Channel Access C API

[Abdalla Ahmad via Tech-talk <tech-talk@aps.anl.gov>]

Hi Ralph

 

The tool I am writing is a simple replacement for CWget and CWput in which I could not compile their sources against base 3.15.6. This tool is used in a specific EDM client in which I have to stick with the current setup.

 

And yes exactly, we are moving towards EPICS Qt instead of CSS so PVTable won’t be used, we are using BURT for the machine but it has SDDS dependencies which we don’t use, never heard of MASAR and for CASR I can’t recall but it might not have been compiled against 3.15.6. Saving and restoring PVs is very basic, no need for such complexities by tools such as BURT.

 

For my question, ca_element_count(channel_id) Did the trick. I still could not figure out how to read the individual elements…

 

Best Regards,

Abdalla.

 

From: Ralph Lange <ralph.lange@gmx.de>
Sent: Thursday, January 23, 2020 2:49 PM
To: EPICS Tech Talk <tech-talk@aps.anl.gov>
Cc: Abdalla Ahmad <Abdalla.Ahmad@sesame.org.jo>
Subject: Re: Read/Write waveforms using Channel Access C API

 

Just to make sure...

 

You are aware that there are a number of existing tools for reading and writing sets of PVs (PVTable in CS-Studio, MASAR, CASR, BURT and others) and you have found them not being solutions to your problem.

 

Cheers,
~Ralph

 

 

On Thu, 23 Jan 2020 at 12:28, Abdalla Ahmad via Tech-talk <tech-talk@aps.anl.gov> wrote:

Hi

 

I am working on a tool which reads a list of PVs (some of which are waveforms) and save those PVs values for later loading them. My problem is with the waveform record, is there a way to know the waveform’s size and read each element? The way I am reading PVs is structured where each DBR type (double, long, enum and string for now) has a struct like this:

 

typedef struct {

                chid channel;

                int status;

                struct dbr_ctrl_TYPE info;

                struct dbr_sts_TYPE data;

}

 

Best Regards,

Abdalla.