Experimental Physics and
Industrial Control System

All,

 

I’ve been using StreamDevice to interface EPICS with some of our instruments and I’ve noticed something interesting for quite some time now. There is one command that I need to send to the instrument occasionally that has a length of around 2000000 chars. Based upon my observations, it takes about 20-30 seconds to send that command through a waveform record and receive a response back through StreamDevice. However, when I use sockets in my C program, it takes about 3-5 seconds.

 

Originally, what I wanted to do was somehow utilize sockets for just that command, while using StreamDevice for the rest of the commands. However, it doesn’t seem to work out since once StreamDevice starts running, I am unable to use sockets in my asub record.

 

I was wondering if anybody has experienced similar behavior with StreamDevice for very long commands and how to potentially speed it up. Should I investigate utilizing asyn or some other drivers, and if so, can it be run in conjunction with StreamDevice? Ideally, it would be nice if I don’t have to migrate from StreamDevice since all the other commands work just fine.

 

Thanks.

Andy