Why does ENET-232 driver use 98% CPU?

[Richard2950]

I have an ENET-232/4 device running under Windows XP Professional and am talking to it using LabVIEW 6.1. I am taking readings from an instrument every 5 seconds, with a small data exchange (6 byte command, response is about 50 bytes). Everything seemed to work just fine, but when left overnight the computer was very sluggish. The nisdsusr process was using 98% of the CPU time, and it continued to do so until I quit LabVIEW. Stopping the vi, which closed the serial port, was not good enough. I re-started LabVIEW and my vi, and I can see the CPU usage jump up to 12%-14% every time I take a reading, and go to basically 0 in between. This is perfectly fine. Why did this process go to 100% CPU usage and how can I prevent it from happen
ing again? I am using the 1.01 serial device server driver, which is the latest version and is XP compatible (aside from the driver signing issue).

[Ray K]

This sounds like a Windows issue. Windows has something called Application boosting(has different names in different OS's) that allocates processor time to some applications over others. Try going to Control Panel>>Performance and Maintenance>>System>>Advanced>>Click on "Settings" in Performance>>Advanced. Choose "Background Services" for Processor Scheduling.

Ray K
NI Applications Engineer

[Richard2950]

OK, I tried that change. It ran over the weekend with no problem, then went into the full CPU usage mode on Monday morning. I stopped LabVIEW and started again. It ran fine until Wednesday morning. Then, while running a vi that had no open serial ports, it went into full CPU usage mode again. I have noticed that it only happens when the screen saver is active. I guess I can disable the screen saver for a test.

Rich

[m3nth]

I know this thread is old, but should anyone happen upon it...

This problem (I've had it too) happens when network communication is lost and the serial device server goes into some kind of loop waiting for a tcp ack that never comes back. Something like that. To fix it the port has to be closed that was being used then re-opened. I'm guessing this was your problem when leaving it to run... at some point network communications were lost and the driver went haywire and didn't recover.

[Emaya]

We have the same problem. We are using 5 ENET to 232 on a LAN with approximately 200 computers, routers and other devices.
We are using the ENET connected to the PBX for call recording of five remote centers. When the communication gets lost the failure happens and it is a problem to restart the system.

There is no solution?

Regards

[Emaya]

We have the same problem. We are using 5 ENET to 232 on a LAN with approximately 200 computers, routers and other devices.
We are using the ENET connected to the PBX for call recording of five remote centers. When the communication gets lost the failure happens and it is a problem to restart the system.

There is no solution?

Regards