I'm told that the OS must re-establish contact with the USB system each time a message is sent to ete, can USB be configured to maintain constant contact with the OS?

glen1 · ‎06-18-2003

My application runs 25% faster with a PCMCIA GPIB than with a USB-B GPIB. I'm calibrating instruments and am not even approaching the 850KB/sec limit of the USB-B, my application consists of short messages to/from the ete. I'm told that the OS must re-establish contact with the USB system each time a short message is sent and that this is where the delay is. Can the USB system be configured to remain in contact with the OS at all times?

DiegoF · ‎06-19-2003

Hi Glen,

This might just be a limitation of the USB bus. The USB protocol defines several transfer modes that you canm use to optimize the data transfer. I'm not sure of what are the setup step to configure a data transfer in USB, but I assume that at least one of this transfer modes should provide continuous data.

I don't think there is a setting in Windows to configure the USB transfers. This is all handled by the device driver.

DiegoF
National Instruments

Instrument Control (GPIB, Serial, VISA, IVI)

I'm told that the OS must re-establish contact with the USB system each time a message is sent to ete, can USB be configured to maintain constant contact with the OS?

I'm told that the OS must re-establish contact with the USB system each time a message is sent to ete, can USB be configured to maintain constant contact with the OS?

Re: I'm told that the OS must re-establish contact with the USB system each time a message is sent to ete, can USB be configured to maintain constant contact with the OS?