Use the COM Port while using XP
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I want to write a program in VB.Net which accesses my computer's COM-Ports. While using windows 98 this is no problem, because there's a DLL which I can use. While using XP this is not possible because of HAL (Hardware Abstraction Layer). I already know that with HAL, it is possible to access COM-Ports by open a file. The problem is that I don't just need the TXD/RXD port but also ports like RI or RTS. How can I manage this? (Maybe there are drivers who create a virtual COM port and translate it to HAL to use the real port?)
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I want to write a program in VB.Net which accesses my computer's COM-Ports. While using windows 98 this is no problem, because there's a DLL which I can use. While using XP this is not possible because of HAL (Hardware Abstraction Layer). I already know that with HAL, it is possible to access COM-Ports by open a file. The problem is that I don't just need the TXD/RXD port but also ports like RI or RTS. How can I manage this? (Maybe there are drivers who create a virtual COM port and translate it to HAL to use the real port?)
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I want to write a program in VB.Net which accesses my computer's COM-Ports. While using windows 98 this is no problem, because there's a DLL which I can use. While using XP this is not possible because of HAL (Hardware Abstraction Layer). I already know that with HAL, it is possible to access COM-Ports by open a file. The problem is that I don't just need the TXD/RXD port but also ports like RI or RTS. How can I manage this? (Maybe there are drivers who create a virtual COM port and translate it to HAL to use the real port?)
No, you can't access the serial ports by simply using IN/OUT instructions as you may have done in DOS. On XP, those I/O ports are restricted to supervisor mode (the kernel). You must use the serial communications APIs. Unfortunately this is one of the less-well documented areas of the Win32 API. To be notified when the Ring Indicator or Clear-To-Send (i.e. the PC's view of the other end's Ready-To-Send line), use the WaitCommEvent[^] API. Stability. What an interesting concept. -- Chris Maunder
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I want to write a program in VB.Net which accesses my computer's COM-Ports. While using windows 98 this is no problem, because there's a DLL which I can use. While using XP this is not possible because of HAL (Hardware Abstraction Layer). I already know that with HAL, it is possible to access COM-Ports by open a file. The problem is that I don't just need the TXD/RXD port but also ports like RI or RTS. How can I manage this? (Maybe there are drivers who create a virtual COM port and translate it to HAL to use the real port?)