MAX recognizes m device, LabVIEW does not.

[tychobrahe1911]

*What am I doing? Trying to interface LabVIEW 7.1 with a USB Garmin GPS18 unit in order to aquire data.

*What have I done thus far? Using the Measurement and Automation explorer and the Device Wizard I have my device recognized. Under Windows Device Manager the GPS18s properties list the Driver Provider as Garmin but the Driver Details tab lists the Provider as National Instruments Corporation. I don't know if this is correct or if somewhere within lies the problem.

*What is the Problem? I've downloaded this sample program and some others just to check and see if LabVIEW recognizes my driver for the GPS unit but it does not. Here is the sample program  http://sine.ni.com/apps/we/niepd_web_display.display_epd4?p_guid=DC76651CD1522404E034080020E74861&p_...

* A little off subject. From what I understand because USB is technically a parallel port device the Instrument I/O Assistant will not work with this device as it only works with serial, GPIB, and Ethernet. Is this correct?

I really appreciate any input I can get.

[Dennis_Knutson]

The device wizard should only be used when the instrument manufacturer does not provide any driver and when the manufacturer provides detailed information on the very low-level USB RAW communication the instrument is using. What you have done is replace the driver that came with the device with a National Instrument VISA interface. What you should do is remove the driver you created with the wizard and re-install any software that came with the GPS. I haven't used this GPS, but it is possible that the USB interface will then appear in MAX as just another serial port. You can then do a search of the forum for GPS drivers. I have seen (but not tried) several examples. They all communicated to the instrument as if it was connected via a regular serial cable.

Even if it was correct that the USB was essentially a parallel port device, VISA and the Instrument I/O Assistant could be used in some cases. It is a fairly simple task to write to a parallel port and use it as a digital output device. The USB is really much more complex than either a simple RS-232 or printer port. The fact is that it can be used for either as well as a host of other commuincation protocols.

[f.grasdepot@laposte.net]

Hi,

that Universal serial bus is essentially a parallel port device seems a
bit cryptic to me. In what sense a serial bus might be a parallel port
device up to you ?

I agree that it is easy to write to a parallel port and it is very
unstandard to read on it ( hardware dependent ). At the contrary, it is
obviously standard to read/write on USB (

Does it exists results on why USB devices are recognized as serial
ports and if so up to which transfer rates are they limited compared to
other serial ports and raw USB transfers ?

My experience is that if they are 30 Euros/USD converters for USB to
serial ports that are bi-directionnal and ... slower than raw serial
ports.

Regards,

FG

[tychobrahe1911]

Okay well the problem is the Measurement & Automation Explorer will not automatically recognize the stock driver. It is for that reason I created a driver. So what I've done since then is I put the stock driver back and tried to create a new port but I still have had no luck.   I guess I will keep trying to figure out what the problem is whether its my own ignorance or an interfacing issue.

[tychobrahe1911]

A fellow co-worker just pointed this out to me so I believe this is indeed an interfacing issue for anyone who is interested.  http://www.gpscentral.ca/accessories/gpsgate18.htm  It appears this software will make life a little easier.

[Dennis_Knutson]

Thanks for the link. It's good to know that there is a workaround. As you've just found out, USB devices don't automatically show up in MAX unless the manufacturer has created an interface that MAX can detect such as a com port or USB-TMC device.