How to detect when a USB modem is connected?

[Akshay07]

Hi all,

I searched the help and the forum and I found lots of info regarding the detection of USB drives or how to communicate with a modem, but nothing that really helped me (unless I missed or misunderstood some information).

I would like to detect automatically when a new modem is connected to the computer via USB, and what is the corresponding COM port. Could someone tell me where to start?

Thank you!

[Sobiech]

Connection mean internet connection or just connected to computer?

Maybe you should look in "_WinNet_" or just use "ping" in cmd ^^

[martin]

Hi all,

I searched the help and the forum and I found lots of info regarding the detection of USB drives or how to communicate with a modem, but nothing that really helped me (unless I missed or misunderstood some information).

I would like to detect automatically when a new modem is connected to the computer via USB, and what is the corresponding COM port. Could someone tell me where to start?

Thank you!

Maybe the links Ptrex gave here could help, but it isn't simple.

You could also check the available COM ports evry 10 seconds say, and if a new one appears then test it with an AT command to see if it's a modem. This will fail if another application is using it though. My serial coms udf (link in my signature) will let you list the available COM ports.

[jchd]

You could also check the available COM ports evry 10 seconds say, and if a new one appears then test it with an AT command to see if it's a modem. This will fail if another application is using it though. My serial coms udf (link in my signature) will let you list the available COM ports.

@Martin,

Isn't it possible, in the case where simple detection is the goal, to monitor the availability of the relevant key in HKEY_LOCAL_MACHINE\HARDWARE\... (forgot where this is enumerated)

@OP,

You may try it at no risk (Read the registry, don't write to it) to see if it works.

[martin]

@Martin,

Isn't it possible, in the case where simple detection is the goal, to monitor the availability of the relevant key in HKEY_LOCAL_MACHINE\HARDWARE\... (forgot where this is enumerated)

Yes, the usb devices ever connected are all supposed to be saved in one place but they are not. The following code will give information on most devices which have been connected to the PC, but I don't know at the moment how you tell if a device is currently connected.

$inst = 1
While 1
    $key = RegEnumKey("HKLM\SYSTEM\CurrentControlSet\Enum\USBSTOR", $inst)
    If @error = -1 Then ExitLoop
    ConsoleWrite($key & @CRLF)
    $sub = 1
    While 1
    $subkey = RegEnumKey("HKLM\SYSTEM\CurrentControlSet\Enum\USBSTOR\" & $key, $sub)
    If @error = -1 Then ExitLoop
    ConsoleWrite(" " & $subkey & @CRLF)
    ConsoleWrite(" DeviceDesc------>" & RegRead("HKLM\SYSTEM\CurrentControlSet\Enum\USBSTOR\" & $key & "\" & $subkey, "DeviceDesc") & @CRLF)
    $sect = StringSplit(RegRead("HKLM\SYSTEM\CurrentControlSet\Enum\USBSTOR\" & $key & "\" & $subkey, "HardwareID"), @LF)
    For $n = 1 To $sect[0]
    ConsoleWrite(" H" & $n & " ------------->" & $sect[$n] & @CRLF)
    Next
    $sub += 1
    WEnd
    $inst += 1
WEnd

My USB to RS232 converter is not listed in the above, it appears in this key

"HKLM\SYSTEM\CurrentControlSet\Services\FTDIBUS"

And nothing seems to change in that key whether the device is plugged in or not.

A useful freeware program that lists all this and more including the connected state is USBDeview.exe by Nirsoft.

[jchd]

Yes, the usb devices ever connected are all supposed to be saved in one place but they are not.

A useful freeware program that lists all this and more including the connected state is USBDeview.exe by Nirsoft.

You're right. I thought that USBed serial pseudo-ports were grouped somewhere and it was a bit late or too early for me to try this by the time I posted my answer. Now that my eyes are reopen (are they really?) I found a couple of these hanging around and they dispatch their registry information all around. That's a Validated Genuine Mess that MS allowed for these simple things.

Thanks for sharing the USBDeview.exe link, which could prove very useful some day. Have fun.

[martin]

The serial ports are listed in the registry at

HKLM\HARDWARE\DEVICEMAP\SERIALCOMM

This list is udated so that plugging in a usb to serial device will add a COM port to the list and unplugging will remove it.

$inst = 1
While 1
    $key = RegEnumVal("HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM", $inst);
    If @error = -1 Then ExitLoop
    ConsoleWrite($inst & ' ' & $key & "--->" & RegRead("HKLM\HARDWARE\DEVICEMAP\SERIALCOMM",$key ) & @CRLF)
    $inst += 1
WEnd

[jchd]

HKLM\HARDWARE\DEVICEMAP\SERIALCOMM

This list is udated so that plugging in a usb to serial device will add a COM port to the list and unplugging will remove it.

I had typed it in my first answer but decided to try it first. Unfortunately I had no pluggable hardware available, so I removed my suggestion after a search for \Device\Serial0 which lead to issues regarding the _mapping_ (local/remote) of serial ports over Terminal Service sessions. You now confirm this is indeed the place where serial devices have their birth and death.

I hope the initial poster keeps on reading the thread.

Thanks Martin and see you later!

[Akshay07]

Thanks to all of you guys, I keep on reading this thread, but I tried mostly in the last days to fully understand how to use Martin's UDF.

Still following up this one

[jchd]

Thanks to all of you guys, I keep on reading this thread, but I tried mostly in the last days to fully understand how to use Martin's UDF.

What do you have difficulty understanding? Are you talking about his COM UDF? We can help, his wrapper works fine.

Is the example registry monitoring Martin posted above working for you?

I mean the HKLM\HARDWARE\DEVICEMAP\SERIALCOMM thing. Is you modem's serial port identified under this key?

[Akshay07]

Thank you jchd and Martin for all your answers!

What do you have difficulty understanding? Are you talking about his COM UDF? We can help, his wrapper works fine.

I know it works very fine, there are enough comments/pages showing this, Martin has followed up on his UDF in an amazing way, and I can see he updated his UDF according to the various comments.

I also saw that he did re-upload his "examples.au3" file very recently (when I tried first to download it, it was not available anymore, but the day after, there was a version "from the same day" available).

The reasons are very simple:

1/ I am absolutely not familiar about the use of serial COM ports in general, so I am trying to understand first how it works before bothering you guys.

2/ I did not have time to concentrate on this (this = retrying it according to your previous comments)

Is the example registry monitoring Martin posted above working for you?

I mean the HKLM\HARDWARE\DEVICEMAP\SERIALCOMM thing. Is you modem's serial port identified under this key?

I wil need some time to look into it. Will come back to you asap, but it might take a few days Edited January 25, 2010 by Akshay07

[Akshay07]

The serial ports are listed in the registry at

HKLM\HARDWARE\DEVICEMAP\SERIALCOMM

This list is udated so that plugging in a usb to serial device will add a COM port to the list and unplugging will remove it.

$inst = 1
While 1
    $key = RegEnumVal("HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM", $inst);
    If @error = -1 Then ExitLoop
    ConsoleWrite($inst & ' ' & $key & "--->" & RegRead("HKLM\HARDWARE\DEVICEMAP\SERIALCOMM",$key ) & @CRLF)
    $inst += 1
WEnd

I tried this and it works, I see new items after connecting a USB Mode.

Actually, I am only interested in the COM value, so I am only interested in RegRead("HKLM\HARDWARE\DEVICEMAP\SERIALCOMM",$key ).

Now that I have a way to detect when a new serial COM port is present, I need to figure out how to communicate with it to ensure that it is a modem.

[jchd]

I tried this and it works, I see new items after connecting a USB Mode.

Actually, I am only interested in the COM value, so I am only interested in RegRead("HKLM\HARDWARE\DEVICEMAP\SERIALCOMM",$key ).

Now that I have a way to detect when a new serial COM port is present, I need to figure out how to communicate with it to ensure that it is a modem.

Sounds good.

Send it AT commands and watch for valid answers. Example dialog:

at
OK
at&v
ACTIVE PROFILE:
B0 E1 L2 M1 Q0 T V1 W0 X4 &C1 &D2 &K3 &Q5 &R1 &S0 &X0 &Y0
S00:000 S01:000 S02:043 S03:013 S04:010 S05:008 S06:003 S07:090 S08:002 S09:006
S10:014 S11:085 S12:050 S18:000 S25:005 S26:001 S36:007 S38:020 S46:138 S48:007
S95:001

TELEPHONE NUMBERS:
0=  1=
2=  3=

OK
atz
OK

Lookup "AT commands" for generic modems, except if you have to deal with highly exotic modems.

[Akshay07]

The AT command part should hopefully not be an issue, but the setting up of the communication with the modem might be.

I just tried to run CommgExample.au3 and it fails immediately.

Edited January 27, 2010 by Akshay07

[Akshay07]

I made a small change regarding the dll path. But after setting up the COM port data, the program ends:

C:\Program Files\AutoIt3\Include\CommMG.au3(149,33) : WARNING: $hDll: possibly used before declaration.

$vDllAns = DllCall($hDll,

C:\Program Files\AutoIt3\Include\CommMG.au3 (273) : ==> Variable used without being declared.:

$vDllAns = DllCall($hDll, 'int', 'SetPort', 'int', $iPort, 'int', $iBaud, 'int', $iBits, 'int', $iPar, 'int', $iStop, 'int', $iFlow, 'int', $RTSMode, 'int', $DTRMode)

$vDllAns = DllCall(^ ERROR

EDIT: My mistake, I incorrectly changed the dll path, both the 1st time and the 2nd time. No more errors.

Edited January 27, 2010 by Akshay07

[jchd]

Don't hesitate to abuse the help file. The one which comes with AutoIt has been specially tailored to sustain an extremely frequent usage and won't wear up until the next release

Seriously, look up the Language topic where you can read that you really should declare any variable before its use. I guess you've corrected that since the error is gone, but keep this good habit.

Keep on learning and best of luck!

[Akshay07]

The AutoIt help is always the first place I look when I need something I found most of my answers in the help.

I actually used to only look at it, and I was reminded in a friendly way that I should also search the forum.

I'll also look into the language topic.

And thanks for your tips, using AutoIt is a never ending learning process

Edited January 27, 2010 by Akshay07