gpib read error during communication with counter

[Skydragon]

I use labview 7.0 with NI gpib card to read Counter continus, sometime it will give me timeout error (6) when I open IE for web or use other windows software at same . It is so strange to know this problem. It should not happen in this way, anyone know why this happen ? My software platform is windowXP .

[Ray K]

The problem is probably that your computer is allocating resources to opening the IE windows and is slowing down the driver. Go to Start»Settings»Control Panel»System»Advanced. Under Performance, click settings. In Visual affects, uncheck Animate Windows. In Advanced, check Background services. Also, increase the GPIB timeout your program uses.

[Skydragon]

I try the way you mentioned, but it seems I still have this problem. in your reply, you mentioned the background services, what's mean of this ? Maybe it is the reason. Because I use CPU time 88% for fully running mode of my counter EG&G 994 in 0.01 gatetime. If I don't touch windows, it may last for about 3 hours without error,but if I touch windows, it will stop soon.
I try to increase gpib timeout ,it seems not help for my problem, any further suggestion ?

Thanks for the reply and it is quite professional . I mark it as 4 star from my viewport

[Ray K]

Starting in Windows NT, Microsoft came up with an optimization what was called application boosting. With application boosting, the operating system allocates resources to the foremost windows application to increase its performance. For example, you have Program A and Program B running at the same time. You click on Program A, bringing it to the front. With application boosting, Windows will allocate more resources to Program A than to Program B. In your case, opening an IE window would make it the foremost Window and take resources away from LabVIEW. Checking background services turns off application boosting.

In LabVIEW, try going to Tools»Options»Performance and Disk and check "Deallocate Memory as soon as Possible".

Also, I assume yo
u have a main loop in your code, put a small wait in the loop. 10 ms will do. This will allow windows to take care of background operations.

[Skydragon]

my system is window xp . and I try to going to Tools->Options->Performance and disk, it is pity that labview 7.0 express don't have this item I can choose.

As for the main loop in my code, I use 30 ms for wait ,it still have this problem.

btw, how to turn off application boosting ?

[Ray K]

I forgot you have LabVIEW 7, version 7 already has that option set by default. App boosting is turned of simply by going to Start»Settings»Control Panel»System»Advanced»Performance»Advanced.

Processor usage of 88% is abnormally high. What is the processor usage when you aren't running your code? See if there is a spike in processor usage or memory usage when you are just opening an IE window without your program running.

[Skydragon]

Thanks for your suggestion and I made it. I find when I use my counter at gatetime 0.01 second, CPU Usage around 77~79% , PF Usage 217MB. when I open IE or other program , it may cause 3-10% more of CPU time. After change the setting of App boosting, the counter seems more stable than before. I will test for 24 hours in continus mode. For our experiments, we need extreme strict working condition of program and hope it can autorunning 24 hours. If this problem still exist, it will be very seriously.