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Is there a way to "force" a com port number for your GPS?
OTR
Is there a way to "force" a comport for you GPS? I want to make a comport just for the GPS. I get different ones assigned every time I boot up. It seems to work best on comport11. Anyone know a way for me to do that? Thanks, OTR
tcassidy
I have no idea why you would get a different one each time you boot up. My USB-COM port is always the same as it is originally generated by the driver. The same applies to my Bluetooth generated COM ports.

What GPS hardware are you using and what type of connection?

Terry
Marvin Hlavac
If your USB GPS receiver is plugged into a different USB port, the com port may be different. Try to use the same USB port each time, and see if it helps.
OTR
Using a MR-350. It seems to come up with 2 or 3 each time. They don't always want to work. I am using a USB connenct
Ken in Regina
Quote:
Originally Posted by tcassidy
I have no idea why you would get a different one each time you boot up. My USB-COM port is always the same as it is originally generated by the driver. The same applies to my Bluetooth generated COM ports.

What GPS hardware are you using and what type of connection?

Terry
I've used the i.Trek M7 on Bluetooth with the laptop three times so far and I've had it change the com port outgoing/incoming on me. The first time it was Com4/Com5. The second time it was the same. The third time it was Com7/Com8.

My Pharos 500 USB receiver (came with Streets&Trips 2008) seems to stay on the same com port every time. I've only used the i.Trek M7 on USB once so I can't say what it will do.

...ken...
tcassidy
Ken,

I think OTR is using a Globalsat 350 on a USB port. The only USB devices that I have seen that make you load a driver on every different USB port are ones with unsigned drivers. I don't have that GPS so couldn't test the driver.

Bluetooth
Assuming you are working with Vista; Right click on the Blutooth symbol in the Notification Bar and choose 'Open Bluetooth Settings'.You should see a list of your Bluetooth devices. Click on 'iBT-GPS' and choose Properties. Click on the Services tab and it should tell you what COM port it is using.

As you are listing incoming and outgoing ports, you might be using a different stack (Toshiba?). So if this doesn't match your setup, let me know. You should never have to change the COM port unless you want to.

Terry
Attached Images
ibtprop.jpg  
Marvin Hlavac
I cannot test anything at the moment, but I'm quite sure that USB GPS receivers will (always?) be at different com ports when we unplug them from one USB port, and then plug them into another USB port.

I'd suggest to OTR to always use the same USB port, and see if it helps.
tcassidy
Marvin,
I tried my S&T GPS on the UMPC (3 USB ports). It always comes up with the same COM port. It can't change COM ports unless the driver is installed more than once.

I don't have an external USB hub at the moment so I can't confirm that this will work with a powered or unpowered hub.

Terry
tcassidy
Marvin,
I also tested the S&T GPS on the Vista HP tablet (3 USB ports) and it always comes up on the same COM port. If you see something different, you have loaded the USB-serial driver that came with the GPS more than once.

Terry
tcassidy
Just for you, I crawled in behind my main computer and installed the S&T GPS on a fixed USB port. I then tried it on a USB port on the monitor (a powered USB hub). Both came up as the same COM port per Device Manager.

Terry
Attached Images
msusb9.jpg  
Marvin Hlavac
Terry, thanks. I'll test it tomorrow morning on my laptop, and I'll post my results here, too.
OTR
I tried mine in a powered USB hub, it did not work at all. I kept getting "unable to open specified port" warnings. I had un-loaded the drivers and re-loaded a new one. I sometimes get different COM ports. When I moved to a different USB port I got a bunch of new ones. I like one of them, it seems to work better. I would love to assign it to the GPS. I wish I knew more about this thing. OTR
Marvin Hlavac
Quote:
Originally Posted by OTR
I sometimes get different COM ports. When I moved to a different USB port I got a bunch of new ones.
What do you mean by "a bunch of"? When you plug a USB GPS receiver into a USB port, you should see only one "new" com port in the Device Manager.
tcassidy
OTR,
As you said you youhad unloaded the driver, I assume you know how to access Device Manager. In case you don't, for Windows XP hold down the Windows key and press Pause. Click on the Hardware tab and then Device Manager button. Click the + sign next to Ports (COM & LPT) to expand that section. When you plug in your GPS to a USB port, you should see ONE COM port added with a name associated with the driver for your GPS.

You might try clicking 'Show Hidden Devices' on the View menu at the top of the Device Manager window and see if more than one instance of this driver shows under that section.

Terry
Marvin Hlavac
I'm now testing this with two USB GPS receivers: GlobalSat BU-353 and Pharos GPS-500 (from Streets & Trips).

My laptop has 3 USB ports.

BU-353 is seen in the Device Manager on the following com ports:

Com Port 4 (when in 1st USB port)
Com Port 6 (when in 2nd USB port)
Com Port 6 (when in 3rd USB port)

The other USB GPS receiver (GPS-500) is always on com port 5 - no matter which USB port I plug it into.

To "force" even the BU-353 to be always on the same com port I did the following:

1. Open Device Manager and go to Ports (if not sure how to do this step, follow Terry's instructions above)

2. Right-click the item you wish to change - In my case I right-clicked: Prolific USB-to-Serial Comm Port (COM4)

3. Click Properties

4. Click Port Settings tab

5. Click Advanced

6. Com Port Number drop-down list will let you select your desired com port number. In my case I changed it from 4 to 6 (so my USB GPS receiver uses #6 no matter which USB port I use)

7. When doing the above step you may be told the com port is in use. Press "Yes" to continue.

Now my BU-353 USB GPS receiver uses com port 6 when plugged into any one of my 3 USB ports .
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