Go Back   TechArena Community > Technical Support > Computer Help > Windows XP > Windows XP Support
Become a Member!
Forgot your username/password?
Tags Active Topics RSS Search Mark Forums Read

Sponsored Links



Usbser.sys CDC Virtual COM Port

Windows XP Support


Reply
 
Thread Tools Search this Thread
  #1  
Old 11-04-2006
Member
 
Join Date: Sep 2005
Posts: 229
Usbser.sys CDC Virtual COM Port

I have some issue regarding the use of the usbser.sys built in windows driver. I have implemented a USB CDC driver in some hardware that I am developing hoping not to have to change Win32 applicatins that currently talk to the device using an RS-232 COM Port. I have generated a .inf file for Windows XP and it installs the usbser.sys driver properly and it works. The Win32 apps can send and receive data over USB from the device as if it was connected to an RS-232 Com Port. The problem is that the device will not remain in the device manager when disconnected. It is of course very reasonable that when you unplug a USB device it is removed from the device manager, however, RS-232 ports are always available! This causes problems in the Win32 apps that are using the port as they have to be re-started (or they at least have to re-connect to the port) each time the device is reconnected to the PC.

Does anyone have any solutions?

Reply With Quote
  #2  
Old 12-04-2006
Member
 
Join Date: May 2006
Posts: 2,328
Re: Usbser.sys CDC Virtual COM Port

I dont think there is anyway to change this. The Com1 and Com2 can also disappear by removal, especially on a laptop because they are in hw dock, or by disabling them in device manager.
Reply With Quote
  #3  
Old 12-04-2006
Member
 
Join Date: Sep 2005
Posts: 229
Re: Usbser.sys CDC Virtual COM Port

Thank you for letting me know about it. I guess that I will have to implement Usb properly.
Reply With Quote
  #4  
Old 04-11-2008
Member
 
Join Date: Nov 2008
Posts: 1
It has been a while since you posted last here.. But I still hope to see your reply!

We are also developing virtual COM port driver. (For the purpose : We have a legacy application that outputs only to COM port and a usb hardware device). We are using usbser.sys as virtual COM port driver. We are able to install the driver successfully.

But when we use Serial COM APIs like CreateFile etc., they fail with GetLastError reporting 2(system can not find specified path). Also if i see device manager -> Ports (COM & LPT) section, the virtual COM driver is listed with an exclaimation mark with below error,-

"Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)"

Do you have any inputs here ? Thanks in advance!

Vijay
Reply With Quote
  #5  
Old 18-01-2009
Member
 
Join Date: Jan 2009
Location: Birminghan UK
Posts: 1
Re: Usbser.sys CDC Virtual COM Port

Hi All,

Just a note here that I had this problem. I got around it by scanning all available com ports a few times a second on a timer until the port I wanted came up and then opened it. Use the code below (VB sorry):-

Sub GetSerialPortNames()
' Show all available COM ports.
For Each sp As String In My.Computer.Ports.SerialPortNames
ListBox1.Items.Add(sp)
Next
End Sub

Regards
Reply With Quote
Reply

  TechArena Community > Technical Support > Computer Help > Windows XP > Windows XP Support
Tags: ,



Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads for: "Usbser.sys CDC Virtual COM Port"
Thread Thread Starter Forum Replies Last Post
USB Virtual Serial Port Warren Hill Hardware Peripherals 1 26-02-2011 12:19 AM
Com1 port not working on virtual box Mercia mAC Operating Systems 5 24-11-2010 12:12 AM
Windows 7 Virtual PC and parallel port dongle Courtenay Operating Systems 4 05-04-2010 01:30 PM
USB Virtual Printer Port Problems Catchkuber XP Hardware 2 05-10-2009 02:22 PM
How do I create a Virtual Port for USB Paul Windows XP Support 3 12-06-2008 10:42 PM


All times are GMT +5.5. The time now is 10:17 AM.