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Edgeport Serial to USB Reference

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    Edgeport Serial to USB Reference

    I am only adding this message as a point of reference should someone serach the message board seeking this related information.

    Today I installed an Edgeport Serial to USB converter on my Pentium 4, WinXP Home PC. The Egdeport device has 8 com ports and my PC only has one com port.

    I had problems getting communication via my CM11A interface, which has occurred before. I also looked at this thread: which describes common problems with the CM11A.

    Once I could get the CM11A to communicate again via the PC's com port, I could not get it to talk thru the Edgeport.

    In looking at the Control Panel (Hardware/device manager/com ports) the reason became clear. The Windows OS maps com ports to meet its needs, which do not map directly to the numbered ports on the Edgeport. This is shown in the device manager.

    For example:

    Com Ports:
    Edgeport Label - PC Assignment
    1 7
    2 8
    3 9

    Obviously these assignments are unique to each PC.


    With XP, USB to serial gizmos often get increasing com port numbers each time the gizmo is pluged into the computer. You can go into the advanced comport setup and reassign the com port numbers back to lower ones you know aren't in use. XP then seems to remember the settings from then on. Something to remember if this starts happening.
    Why I like my 2005 rio yellow Honda S2000 with the top down, and more!


      COM ports

      Yes. XP will save the com ports that have been used and any new ones added start from there and go up. They are called PHANTOM PORTS.

      There is a way to reset and remove these unused ports so that they can be reused. It does require using REGEDIT and changing one field. Quick and easy but it is an edit to the registry.

      If anyone is interested, I have the procedure and will be happy to supply it to anyone that would like it.


      I have performed the edit a few times and it does work.

      I used it when I had a Digi 8 port PCI serial card and again when I went to using the EDGEPORT USB to SERIAL external units. Both worked great after the edit and reset to the port assignments I wanted to use.


        So Shawn did a simple re-assignment of the com port that the CM11A was using fix you problems? How did you determine which com port the CM11A was plugged into?
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          Below is a link showing the simple reasignment of the comport number in device manager. Once the port is reassigned, xp seems to remember correctly from then on.

          Why I like my 2005 rio yellow Honda S2000 with the top down, and more!


            I just reinstalled my server the other day and so had to setup my EdgePort/8, so this is fresh in my memory.

            When I installed it, it set the Edgeport ports to COM 5-12 (I have 2 built in ports on the motherboard). I reassigned those to COM 3-10 as they were before using the EdgePort Configuration Utility.

            This should be installed when you install the driver. If not, go to to get the latest driver which WILL have the utility. It will also let you rename the EdgePort/8 to something else (which will then show in various dialogs including Device Manager). Lots of other things you can set in here.

            Never had on moment's problem with my Edgeport since the day I bought it off eBay. VERY reliable piece of hardware (though pricey if you buy them new, cheap off eBay).

            Currently only using 5 ports off it for now:

            1. HomeSeer connection to Ocelot
            2. HomeSeer connection to MR26A
            3. HomeSeer connection to HAI Omni Pro II (not currently running plugin)
            4. CMAX connection to Leopard II (only used for programming - normally Leo hooked to anothe HAI COM port)
            5. PC Access connection to HAI Omni Pro II (for programming, etc w/o disturbing HomeSeer)

            Not using a CM11a at all, so can't speak to how well it works off the EdgePort.


              If you are using the hardware con ports 1 and 2, then I would start the virtual comports at 5 and up. Hardware wise, I think com ports 1 and 3, and 2 and 4 use the same interrupts. This might cause confusion when com1 and com3 are used at the same time.
              Why I like my 2005 rio yellow Honda S2000 with the top down, and more!


                This is all very useful information; it's been quite a while since I've dabbled in the world of com ports.

                Rupp - I was able to view the com port assignments using the hardware device manager view in WinXP. It displays the computers assignment and how it is mapped to the Edgeports com port assignment. I now have my CM11A and W800 running thru the Edgeport and they work great.

                Everyone else watch your ears for a moment while I thank Rupp....


                Not that I didn't owe you already, but this one really made my day - 8 com ports via USB for 25 bucks.

                PS. I'd be interested in that reg edit for future use.


                  I installed my Edgeport/8 long ago under XP, starting with COM5.
                  It has never faltered - always boots up and goes.

                  So it IS possible to write good add-on port drivers for Windoze - they did it.



                    Actually under Windows NT, 2000, or XP, it doesn't matter. You can start them at COM3 without problems.

                    The issue was that under DOS (and to some degree this includes Win 95/98/ME) the machine assumed that the COM ports were setup as follows (port, i/o address, irq):

                    COM1 3F8 IRQ 4
                    COM2 2F8 IRQ 3
                    COM3 3E8 IRQ 4
                    COM4 2E8 IRQ 3

                    And thus this DID matter. However, even back in the DOS days you get get COM ports (which were hard to find) that would let you use IRQs other than 3 or 4 (for instance 5, 7, or 2/9) that would still let you have 4 ports, all different IRQs. (or with an Xacto knife and a soldering iron you could take a standard ISA serial card and change its IRQ...)

                    On Windows NT/2000/XP, it really doesn't matter what the COM ports are on. Even if they are on the same IRQ it doesn't matter... In fact when talking about a device such as the EdgePort/8, all the ports on it *ARE* on the same IRQ (by definition). This would be the USB IRQ.

                    Under Windows nowadays, serial ports don't have to be based on a specific IRQ and I/O address. You just write a device driver which exports a device called \Devices\SerialX (where X is the serial port) and then create a Symbolic Link to \DosDevices\COMY (where Y is the COM port you want assigned), or I think in more "modern" WIndows XP terminology this is actually \??\COMY. When you then access COMY, it maps back to the underlying \Devices\SerialX device, which maps to the driver (in this case the EdgePort driver) which figures out how to talk to the serial port. Windows itself doesn't care HOW you implement the serial port. (excuse me if I have the device names slightly off - its been about 8 years since I wrote low level Windows code, but had written quite a few Windows NT kernel drivers in my days).

                    This is why its so straightforward (and easy if you're familiar to the Windows DDK) to write a serial port driver that works over the network, and your apps don't know the difference (assuming the remote device is there)...

                    Anyways, hope this helps.


                      Thanks for the info. I'm currently working in the "near DOS" world of cmd.exe. XP is pretty accomidating in allowing echoing bytes to the com port. I can echo bytes to the virtual com ports 5 and above too. No way to get bytes from the input buffer this way. I've got a beginner VB book with the VB learning edition, but not much info on developing simple command line applications to use with a web server and such. Still looking for a simple way to access the input buffer.
                      Why I like my 2005 rio yellow Honda S2000 with the top down, and more!