Modern Laptops and COM ports

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JohnMat

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It seems that modern laptops have abandoned serial or COM (RS232) ports but many NMEA input devices still have serial outputs (eg AIS, Navtex etc), and the serial to USB converters which are necessary for input to current laptops, seem to "lose" their COM port identity (they may be designated to any COM port) and that means one has to change the application settings each time.
I think I may have found a solution to this problem, there are devices sold that are multiple serial to a single USB converters that have COM port RETENTION. I have a 4 COM port converter made by StarTech.com, (they also make them with 1 to 4 COM ports).
To date this has solved the problem of "migrating" COM ports and the COM port identities are retained through every re-boot.
I hope my experience is useful to others as I found this very frustrating previously. JohnMat
 
I Have seen this problem mentioned on other threads and a wee bit curious because I have a few of these devices used for controlling or programming
Ham radios etc and non of them exhibit this problem and always seem to retain the setting. In some cases where the setting has been dictated but outside the
range of the software then they have retained the Com port setting I have reset to in Device settings. I have noted you comments in case the problem does occur :)
 
if the usb to serial converter cable is plugged back into the same previously used usb port then it quite often does pick up the same COM port allocation... but it's those times when it doesn't that get a little annoying..

as John Mat suggests, I also use the StarTech four port converter and with the COM port retention, the issue never arises.

It is also good in that you can allocate the ports as you wish e.g COM 1 to COM 4 and they are retained.
 
JohnMat said:
It seems that modern laptops have abandoned serial or COM (RS232) ports but many NMEA input devices still have serial outputs (eg AIS, Navtex etc), and the serial to USB converters which are necessary for input to current laptops, seem to "lose" their COM port identity (they may be designated to any COM port) and that means one has to change the application settings each time.
I think I may have found a solution to this problem, there are devices sold that are multiple serial to a single USB converters that have COM port RETENTION. I have a 4 COM port converter made by StarTech.com, (they also make them with 1 to 4 COM ports).
To date this has solved the problem of "migrating" COM ports and the COM port identities are retained through every re-boot.
I hope my experience is useful to others as I found this very frustrating previously. JohnMat
Click to expand...

You are puzzling me. I use the prolific software converter and that never loses the port identity. Is it your chart software that is losing its port identity each boot up? Again that puzzles me because the charting software I use on the lappy looks for the same port each boot up. And whats this about manufacture? Pleas elucidate ( todays long word!)
 
Its almost always when you plug into different USB ports. So lets say you have 3 USB ports on a laptop and maybe have a smartphone which you might charge/download pictures from, a mouse, and a USB stick plus a COM port adaptor. If you regularly plug these into "whatever port is free" you run into issues. But there is something to do with how the computer internally is wired up too that means if it has internally a hub it may either allocate to other devices in a random order on boot depending what is plugged in etc.

An external USB hub sometimes makes that better... sometimes not...
 
JohnMat said:
I think I may have found a solution to this problem, there are devices sold that are multiple serial to a single USB converters that have COM port RETENTION...
Click to expand...

You mean the ones I've been recommending for like forever?

FTDI USB to Serial RS232 Adapter Cable with COM Retention:
Single port version: http://amzn.to/1cEOL4h
Dual port version: http://amzn.to/1ccP1fG

Personally I think the dual version is the best bet, it gives some redundancy. I've got three of them!

#USBRS232
 
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I use Maxsea software which has an auto-connection wizard so any devices such as a USB/GPS dongle are identified and activated. Ideal for less tekkie users such as myself
 
I think you've been lucky or I've been unlucky as I have 3 "talkers" to plug in and when I had each connected through a Prolific converter, and I carefully plugged into the same USB ports, I would get ports re-designated. It may well be a feature of the laptop design, mine is a Lenovo X200 and the software is SeaPro 3000.
JohnMat
 
claymore said:
I use Maxsea software which has an auto-connection wizard so any devices such as a USB/GPS dongle are identified and activated. Ideal for less tekkie users such as myself
Click to expand...

I have a USB connected GPS puck that doesn't have port retention and I use a (free) program called XPORT that allows you to define the COM port settings yourself..
 
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... at least it's not the Prolific chipset!

It uses the TIUSB3410 Texas Instruments as a base and I've found it 100% solid with both XP and Windows 7.. and working with serial to USB cables every day at work I totally know what it's like to have a bad/Prolific cable...
 
.. and I shouldn't be surprised..

but what did surprise me about that Startech 4 port box was that it was quite capable of converting two NMEA streams at 4800, one stream at 38400 inbound towards the laptop.. and simultaneously allowing us to dial out through the fourth port via a serial connection on a Satellite phone terminal to download GRIB files.

It's now installed behind panelling and we just have a single USB cable end appearing at the chart table. All NMEA/Serial is hidden away.
 
Martin_J said:
.. and I shouldn't be surprised..

but what did surprise me about that Startech 4 port box was that it was quite capable of converting two NMEA streams at 4800, one stream at 38400 inbound towards the laptop.. and simultaneously allowing us to dial out through the fourth port via a serial connection on a Satellite phone terminal to download GRIB files.

It's now installed behind panelling and we just have a single USB cable end appearing at the chart table. All NMEA/Serial is hidden away.
Click to expand...

Amazing - can it cook breakfasts?
 
Joking aside, I've never had a problem with the Prolific chipset devices. I've a single and a dual port and they always get assigned the same COM numbers if plugged into the same USB port. Even if they didn't though it would take only a few seconds to assign the desired port number.

£6.99 for a dual port adapter compared to the £33 for the one in the link above.
 
I believe you, Nigel. My GPS dongle for the XP notebook is supposed to run on the Prolific setup but, for the life of me, I can't get it to recognise the bloody thing. Have downloaded the latest driver and old drivers, but just cannot get it to show up under the Device Manager > Hardware > Port (Com & LPT) tab. :(
 
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