# Cannot open COM 1 Error (for GPS device)



## akstacey88 (Jul 26, 2005)

Hi, I have a problem concerning connecting a laptop to a GPS system. I purchased a laptop to use with my GPS system. I have a connector that connects to my GPS via a small serial port to the laptop via a USB port. I installed the software the be used and I am getting an error.

It states that COM 1 is already open or cannot open COM 1. I have no other devices that I am using with my laptop, only the GPS. I am running Windows XP Home. My laptop meets all software requirements. Others I know are using the same software and same GPS as me and it works fine. I do not know a lot about computers, so any help in getting this fixed would be appreciated.

Thank You.


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## Rollin' Rog (Dec 9, 2000)

I'm going to move you to the hardware forum for this. But try going to the Device Manager and double click the com ports device. Make sure the device is enabled and "working properly". Under "resources" there is a default check in "use automatic settings". I don't know what removing that check and selecting another "configuration" does.

Under "port settings" advanced, though there may be some settings that need changing there -- you should probably consult the GPS device tech support for that. But you will see a little drop down box which will tell you which com ports are "in use".


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## akstacey88 (Jul 26, 2005)

I went into Device Manager and checked to see that the COM ports were working ok and they were. COM 1 is picking up the device that I have connected to my computer to connect to the GPS.


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## Rollin' Rog (Dec 9, 2000)

And yet the device is not functioning due to the error?

Was the software installed before or after the device was connected? With USB devices normally one installs the software first and then connects the device -- but I'm not sure if that always applies since you are going from a serial port to a USB one.

Does unplugging the device and reconnecting it have any effect?

I wish I had more for you on this, perhaps someone else will. But if it were mine, I'd be on the phone to their tech support if they have a free line -- or at least emailing them through their Website. If they don't have one, I'd return the device.


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## akstacey88 (Jul 26, 2005)

I first tried installing the software first and then connecting the device. I then tried uninstalling it, connecting the device frist and then installing and it made no difference.

I tried reconnecting the device and I still get the error. I have emailed the software manufacturer in hopes that they will respond to me. Everything seems to look ok, so I can't figure out what the problem is.

But I have a question that maybe someone would know....Would it help if I took all other USB connected devices off the computer (ie. mouse, printer...) and tried it then? Is it possible that another device is using COM 1?

Thanks,
Allison


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## Rollin' Rog (Dec 9, 2000)

The devices that would use a "serial" port would need to be connected to the computer serial port jack (if it had one) or through an adapter, such as you are using. Mostly only "legacy" mice and some printers do this.

However it won't hurt to test doing that as USB ports do have both bandwidth and power limitations which can be exceeded. Make sure you are connecting directly to the hub -- or if a multii-port adapter is used, that it is self powered.

If your device is detected and recognized though -- that's about all you can expect of Windows. The rest is up to the software.


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## JohnWill (Oct 19, 2002)

I hate to suggest the obvious, but have you contacted the maker of the GPS unit?


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## akstacey88 (Jul 26, 2005)

I have contacted the maker of the GPS and the maker of the software and got a very general response back. They basically said that there must be some other device using COM 1. Which I kind of figured anyways. But we only have the one serial device connected through USB. Tonight i will try removing all USB ports and leaving in just the GPS and re-installing the software. It is worth a try since I cant seem to get it figured out! Any one else got anything for me to try?


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## Rollin' Rog (Dec 9, 2000)

Try running *msinfo32* and check to see what IRQ Com Port 1 is on. Then check the IRQs list and see if anything else is on it. Check the Modem as well and see what port that is on -- since it is a serial device as well.


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## JohnWill (Oct 19, 2002)

If you uninstall the software for the GPS, you can check and see if there's a COM1 already present. You may have to disable it in the BIOS if it's an on-board port. It would help to know something about the system...


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## akstacey88 (Jul 26, 2005)

The computer is a COMPAQ laptop, 512 MB RAM, 2.4 GHz Processor, Windows XP Home Edition. It has a mouse and printer attached via USB and it has ports for a monitor and a larger printer serial port. It also has slots for the SD and other cards for digital cameras. Im going to try everyones suggestions the weekend. Hopefully I will get it to work!!!


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## kiwiguy (Aug 17, 2003)

I assume that you are using a USB to Serial RS232 COM Port adapter plugged into the USB on the laptop?

These will not usually map to COM1, as COM 1 and COM 2 are "hardware ports" (which may or may not exist of your laptop) while the USB adapter will mapt to a higher port nimber as a "virtual port" such as COM 5, and only exist in software.

Not all serial connected device drivers such as GPS etc are made to use such "virtual ports" and thats where problems arise. I have about a 50% success rate with such devices, they vary by make and model of both the adapter and the device driver for the device you are connecting.

Try setting the software to a COM port above COM 1, (internal laptop modems are also :virtual ports" usually using COM 3)

One of the main reasons my last laptop prurchase was decided by the presence of a real COM port on the back.


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## akstacey88 (Jul 26, 2005)

Yes I am using a device to connect the "serial" GPS port to the computer's USB port - since my computer dosent't have a seral port to fit it. So you suggest trying to set the software to connect using COM Port 4 or 5? In device manager would have have to set the device to connect the GPS and Laptop to COM 4 or 5 too? Thanks!


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## kiwiguy (Aug 17, 2003)

The converter device should have created the "virtual port" when installed.

The PC needs to be set (in the GPS softe=ware" to use that virtual port, which is likely to be a higher numbred one. If the port does not exist in the selection of available ports either the GPS PC software does not support the virtual port or the PC has not set it up correctly.

The question you needed to ask the GPS people is if the software works with virtual USB to RS232 ports, its possible that some software just will not do so.

Its hard to be specific as you have at no time mentioned what the GPS unit is, or what the software is. My crystal ball is not able to tell me either, sorry!


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## akstacey88 (Jul 26, 2005)

Thanks for your response. The GPS im using is FURUNO and the software im using is MaxSea. It is for use on a boat. Other people have the same GPS and the same connector to link the GPS and the laptop and same software, and it works fine on theirs. So I think its just a setting on the computer or in the software. My software does allow for COM ports up to 4 I believe. I'm going to fool around with it some more. The laptop cost $2000 and was bought specifically to use on the boat with the GPS. So you think it is possible to be fixed?


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