Hi,
I’m working to develop a Virtual COM Port and i don’t know if the best thing
to do is to create a driver that will connect to serial.sys to send the
requests ? Maybe the best thing is to create a driver that don’t need to
talk with serial.sys.
Thanks.
“huh”…
Why do you think you have to have anything to do with serial.sys?
Are you making a virtual port of another medium OR
Exposing the ‘real’ serial port over something like a network from the
machine?
BR,
Rob Linegar
Software Engineer
Data Encryption Systems Limited
www.des.co.uk | www.deslock.com
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Francky
Sent: 26 July 2005 16:30
To: Windows System Software Devs Interest List
Subject: [ntdev] Question about Virtual COM Port
Hi,
I’m working to develop a Virtual COM Port and i don’t know if the best
thing
to do is to create a driver that will connect to serial.sys to send the
requests ? Maybe the best thing is to create a driver that don’t need to
talk with serial.sys.
Thanks.
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@des.co.uk
To unsubscribe send a blank email to xxxxx@lists.osr.com
I have an application connected to a com port that receive data from a GPS.
Sometime the GPS is connected to a COM Port and sometime on a USB port.
“Rob Linegar” wrote in message news:xxxxx@ntdev…
“huh”…
Why do you think you have to have anything to do with serial.sys?
Are you making a virtual port of another medium OR
Exposing the ‘real’ serial port over something like a network from the
machine?
BR,
Rob Linegar
Software Engineer
Data Encryption Systems Limited
www.des.co.uk | www.deslock.com
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Francky
Sent: 26 July 2005 16:30
To: Windows System Software Devs Interest List
Subject: [ntdev] Question about Virtual COM Port
Hi,
I’m working to develop a Virtual COM Port and i don’t know if the best
thing
to do is to create a driver that will connect to serial.sys to send the
requests ? Maybe the best thing is to create a driver that don’t need to
talk with serial.sys.
Thanks.
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@des.co.uk
To unsubscribe send a blank email to xxxxx@lists.osr.com
I have an application connected to a com port that receive data from a GPS.
Sometime the GPS is connected to a COM Port and sometime on a USB port.
“Francky” wrote in message news:xxxxx@ntdev…
> Hi,
>
> I’m working to develop a Virtual COM Port and i don’t know if the best
thing
> to do is to create a driver that will connect to serial.sys to send the
> requests ? Maybe the best thing is to create a driver that don’t need to
> talk with serial.sys.
>
> Thanks.
>
>
>
Why do you think you need a driver at all? USB to serial has been around for
years, and virtualizing a COM port is without a doubt one of the most
difficult driver tasks to undertake. Unless you have tons of kernel
experience and mega-mandays it is NOT recommended. Since you state that you
already have a serial connection capability, again I ask, "Why do you think
you need a “virtual COM port”?
–
The personal opinion of
Gary G. Little
“Francky” wrote in message news:xxxxx@ntdev…
>I have an application connected to a com port that receive data from a GPS.
> Sometime the GPS is connected to a COM Port and sometime on a USB port.
>
> “Francky” wrote in message news:xxxxx@ntdev…
>> Hi,
>>
>> I’m working to develop a Virtual COM Port and i don’t know if the best
> thing
>> to do is to create a driver that will connect to serial.sys to send the
>> requests ? Maybe the best thing is to create a driver that don’t need to
>> talk with serial.sys.
>>
>> Thanks.
>>
>>
>>
>
>
>
I want to use Virtual COM because sometime a have several applications that
need to get the data from the physical COM or from the USB.
“Francky” wrote in message news:xxxxx@ntdev…
> Hi,
>
> I’m working to develop a Virtual COM Port and i don’t know if the best
thing
> to do is to create a driver that will connect to serial.sys to send the
> requests ? Maybe the best thing is to create a driver that don’t need to
> talk with serial.sys.
>
> Thanks.
>
>
>
I have several applications connected to a com port at the same time that
receive data from a GPS.
Sometime the GPS is connected to a COM Port and sometime on a USB port.
I want to use Virtual COM because sometime a have several applications that
need to get the data from the physical COM or from the USB. What’s to best
way to do that ?
Thanks for your help.
Several applications accessing one exclusive resource could be
abstracted using a COM object (the object type not the serial type…) or
maybe a DLL with shared data and relevant blocking etc for access from
multiple applications.
Unless all the app’s talk to a COM port.
In which case (bit of a shot in the dark at your needs) but you’d need a
driver that abstracts incoming data to virtual COM port(s?) for
reading by your suite of applications? Not fun…
Still a bit fuzzy about your needs. Is USB not coming in via a
USB->Serial bridge driver already?
BR,
Rob Linegar
Software Engineer
Data Encryption Systems Limited
www.des.co.uk | www.deslock.com
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Francky
Sent: 27 July 2005 01:32
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Question about Virtual COM Port
I want to use Virtual COM because sometime a have several applications
that
need to get the data from the physical COM or from the USB.
“Francky” wrote in message
news:xxxxx@ntdev…
> Hi,
>
> I’m working to develop a Virtual COM Port and i don’t know if the best
thing
> to do is to create a driver that will connect to serial.sys to send
the
> requests ? Maybe the best thing is to create a driver that don’t need
to
> talk with serial.sys.
>
> Thanks.
>
>
>
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@des.co.uk
To unsubscribe send a blank email to xxxxx@lists.osr.com
Multiple applications sharing an exclusive device is a bit strange.
Each application expects to have exclusive access to the com port and be
able to read data, change hw settings, etc. If you did this and if 2
apps request different hw settings, one will be broken. If one app is
reading data, will the other app lose that data or will you duplicate
it?
d
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Francky
Sent: Tuesday, July 26, 2005 10:58 AM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Question about Virtual COM Port
I have an application connected to a com port that receive data from a
GPS.
Sometime the GPS is connected to a COM Port and sometime on a USB port.
“Francky” wrote in message
news:xxxxx@ntdev…
> Hi,
>
> I’m working to develop a Virtual COM Port and i don’t know if the best
thing
> to do is to create a driver that will connect to serial.sys to send
the
> requests ? Maybe the best thing is to create a driver that don’t need
to
> talk with serial.sys.
>
> Thanks.
>
>
>
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
All applications are already developed to connect on a COM port to receive
the data from a GPS device (Serial, USB).
All apps need to receive the same data but only one of them will write on
the device to initialise it.
“Doron Holan” wrote in message
news:xxxxx@ntdev…
Multiple applications sharing an exclusive device is a bit strange.
Each application expects to have exclusive access to the com port and be
able to read data, change hw settings, etc. If you did this and if 2
apps request different hw settings, one will be broken. If one app is
reading data, will the other app lose that data or will you duplicate
it?
d
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Francky
Sent: Tuesday, July 26, 2005 10:58 AM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Question about Virtual COM Port
I have an application connected to a com port that receive data from a
GPS.
Sometime the GPS is connected to a COM Port and sometime on a USB port.
“Francky” wrote in message
news:xxxxx@ntdev…
> Hi,
>
> I’m working to develop a Virtual COM Port and i don’t know if the best
thing
> to do is to create a driver that will connect to serial.sys to send
the
> requests ? Maybe the best thing is to create a driver that don’t need
to
> talk with serial.sys.
>
> Thanks.
>
>
>
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
AFAIK its not possible to open a COM port from multiple apps so the kind
of problems Doran described wouldn’t happen.
Now you’ve shed more light on what you need it’s easier to understand
your needs.
This isn’t really a driver issue now, but an issue of getting incoming
serial port data to multiple applications.
There are two options I can see.
The first, and more simple is to make a user mode DLL or COM object that
farms the incoming data out to the relevant applications like I
described before. This however means that the applications will need to
change.
If it isn’t possible to change the applications the other option would
be to write a driver that exposes multiple virtual serial port
interfaces and talks to serial.sys itself. Almost like a filter driver
that exposes more COM ports for the underlying ‘real’ port.
It’s pretty easy to write a driver that does the actual serial
communications. However translating that back to multiple serial ports
that ‘get’ the same data back isn’t quite so easy… Shadowing one port
into another by using a filter wouldn’t be that hard a job however
multiplexing that out to multiple ports would be a lot more involved.
Why do all these applications need access at the same time?
Can’t it be limited to one at a time? It’d save a heap of hassle.
BR,
Rob Linegar
Software Engineer
Data Encryption Systems Limited
www.des.co.uk | www.deslock.com
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Francky
Sent: 27 July 2005 17:49
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Question about Virtual COM Port
All applications are already developed to connect on a COM port to
receive
the data from a GPS device (Serial, USB).
All apps need to receive the same data but only one of them will write
on
the device to initialise it.
“Doron Holan” wrote in message
news:xxxxx@ntdev…
Multiple applications sharing an exclusive device is a bit strange.
Each application expects to have exclusive access to the com port and be
able to read data, change hw settings, etc. If you did this and if 2
apps request different hw settings, one will be broken. If one app is
reading data, will the other app lose that data or will you duplicate
it?
d
-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com] On Behalf Of Francky
Sent: Tuesday, July 26, 2005 10:58 AM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Question about Virtual COM Port
I have an application connected to a com port that receive data from a
GPS.
Sometime the GPS is connected to a COM Port and sometime on a USB port.
“Francky” wrote in message
news:xxxxx@ntdev…
> Hi,
>
> I’m working to develop a Virtual COM Port and i don’t know if the best
thing
> to do is to create a driver that will connect to serial.sys to send
the
> requests ? Maybe the best thing is to create a driver that don’t need
to
> talk with serial.sys.
>
> Thanks.
>
>
>
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@windows.microsoft.com
To unsubscribe send a blank email to xxxxx@lists.osr.com
—
Questions? First check the Kernel Driver FAQ at
http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: xxxxx@des.co.uk
To unsubscribe send a blank email to xxxxx@lists.osr.com
(1) Com ports are exclusive. If you look at the serial driver in the ddk it
will fail the open request if the port is already open. Plus changing this
is not recommended because serial.sys was designed for exclusive access.
(2) You could write a Virtual Com Driver that will open the real serial.sys
and pass all the data to all Virtual Com ports that the virtual driver
creates. A big task but of course do able. This will have to be a bus
driver.
(3) Trying to be creative you MAY be able to write a filter driver for the
serial.sys that could “transform” the serial.sys to allow more than one
process to have say the com port open and to get the reads. This is not
trival.
(4) Number 2 I know will work I have done something similiar. Number 3 I
just thought of now and I not completely sure.
Sincerely;
Mike Jones
“Francky” wrote in message news:xxxxx@ntdev…
> Hi,
>
> I’m working to develop a Virtual COM Port and i don’t know if the best
thing
> to do is to create a driver that will connect to serial.sys to send the
> requests ? Maybe the best thing is to create a driver that don’t need to
> talk with serial.sys.
>
> Thanks.
>
>
>
I will try to do a filter driver that talk with serial.sys.
Thanks.
“Michael Jones” wrote in message
news:xxxxx@ntdev…
> (1) Com ports are exclusive. If you look at the serial driver in the ddk
it
> will fail the open request if the port is already open. Plus changing this
> is not recommended because serial.sys was designed for exclusive access.
> (2) You could write a Virtual Com Driver that will open the real
serial.sys
> and pass all the data to all Virtual Com ports that the virtual driver
> creates. A big task but of course do able. This will have to be a bus
> driver.
> (3) Trying to be creative you MAY be able to write a filter driver for the
> serial.sys that could “transform” the serial.sys to allow more than one
> process to have say the com port open and to get the reads. This is not
> trival.
> (4) Number 2 I know will work I have done something similiar. Number 3 I
> just thought of now and I not completely sure.
>
> Sincerely;
> Mike Jones
>
> “Francky” wrote in message news:xxxxx@ntdev…
> > Hi,
> >
> > I’m working to develop a Virtual COM Port and i don’t know if the best
> thing
> > to do is to create a driver that will connect to serial.sys to send the
> > requests ? Maybe the best thing is to create a driver that don’t need to
> > talk with serial.sys.
> >
> > Thanks.
> >
> >
> >
>
>
>
(1) I have to respond about doing a filter driver for serial.sys.
(2) One this may not work. Here is how I understand what you are trying to
do. You have more than one process running both opening say COM1: All the
processes will get the same data on reading from COM1:
(3) The other way is by writing a Virtual Bus Driver that creates say COM7:
COM8: COM9: etc. this you can configure. Each of these can be exclusive:
The Virtual Bus Driver will open say COM1: and then send the same data to
COM7: COM8: COM9: etc. This I know works.
(4) You could could also create also create a single Virtual Serial Port
Driver that creates a single port say COM7: that opens say COM1: but allow
multiple access on this COM7:
(5) You could also create the above Virtual Bus Driver that creates like
step (2) above but allows multilple access on the Virtual Com ports COM7:
COM8: COM9:
(6) !!! The only one I have done is 3 and I know this works - why
because I have done. All the others are Research and Development.
(7) Contact me via email or this list server if I help more. Would love to
work with you on this. Multiplexing an Exclusive Access Device sounds cool.
Sincerely;
Mike Jones
“Francky” wrote in message news:xxxxx@ntdev…
> I will try to do a filter driver that talk with serial.sys.
>
> Thanks.
>
>
> “Michael Jones” wrote in message
> news:xxxxx@ntdev…
> > (1) Com ports are exclusive. If you look at the serial driver in the ddk
> it
> > will fail the open request if the port is already open. Plus changing
this
> > is not recommended because serial.sys was designed for exclusive access.
> > (2) You could write a Virtual Com Driver that will open the real
> serial.sys
> > and pass all the data to all Virtual Com ports that the virtual driver
> > creates. A big task but of course do able. This will have to be a bus
> > driver.
> > (3) Trying to be creative you MAY be able to write a filter driver for
the
> > serial.sys that could “transform” the serial.sys to allow more than one
> > process to have say the com port open and to get the reads. This is not
> > trival.
> > (4) Number 2 I know will work I have done something similiar. Number 3
I
> > just thought of now and I not completely sure.
> >
> > Sincerely;
> > Mike Jones
> >
> > “Francky” wrote in message
news:xxxxx@ntdev…
> > > Hi,
> > >
> > > I’m working to develop a Virtual COM Port and i don’t know if the best
> > thing
> > > to do is to create a driver that will connect to serial.sys to send
the
> > > requests ? Maybe the best thing is to create a driver that don’t need
to
> > > talk with serial.sys.
> > >
> > > Thanks.
> > >
> > >
> > >
> >
> >
> >
>
>
>
It could be interesting to use the Virtual bus driver idea.
I’ve created a template of Virtual Serial Driver with DriverStudio and that
seem to be a good departure.
I started my driver like you said in your idea #5.
If you can help me you are .
“Michael Jones” wrote in message
news:xxxxx@ntdev…
> (1) I have to respond about doing a filter driver for serial.sys.
> (2) One this may not work. Here is how I understand what you are trying
to
> do. You have more than one process running both opening say COM1: All
the
> processes will get the same data on reading from COM1:
> (3) The other way is by writing a Virtual Bus Driver that creates say
COM7:
> COM8: COM9: etc. this you can configure. Each of these can be exclusive:
> The Virtual Bus Driver will open say COM1: and then send the same data to
> COM7: COM8: COM9: etc. This I know works.
> (4) You could could also create also create a single Virtual Serial Port
> Driver that creates a single port say COM7: that opens say COM1: but allow
> multiple access on this COM7:
> (5) You could also create the above Virtual Bus Driver that creates like
> step (2) above but allows multilple access on the Virtual Com ports COM7:
> COM8: COM9:
> (6) !!! The only one I have done is 3 and I know this works - why
> because I have done. All the others are Research and Development.
> (7) Contact me via email or this list server if I help more. Would love
to
> work with you on this. Multiplexing an Exclusive Access Device sounds
cool.
>
> Sincerely;
> Mike Jones
>
>
>
> “Francky” wrote in message news:xxxxx@ntdev…
> > I will try to do a filter driver that talk with serial.sys.
> >
> > Thanks.
> >
> >
> > “Michael Jones” wrote in message
> > news:xxxxx@ntdev…
> > > (1) Com ports are exclusive. If you look at the serial driver in the
ddk
> > it
> > > will fail the open request if the port is already open. Plus changing
> this
> > > is not recommended because serial.sys was designed for exclusive
access.
> > > (2) You could write a Virtual Com Driver that will open the real
> > serial.sys
> > > and pass all the data to all Virtual Com ports that the virtual driver
> > > creates. A big task but of course do able. This will have to be a bus
> > > driver.
> > > (3) Trying to be creative you MAY be able to write a filter driver for
> the
> > > serial.sys that could “transform” the serial.sys to allow more than
one
> > > process to have say the com port open and to get the reads. This is
not
> > > trival.
> > > (4) Number 2 I know will work I have done something similiar. Number
3
> I
> > > just thought of now and I not completely sure.
> > >
> > > Sincerely;
> > > Mike Jones
> > >
> > > “Francky” wrote in message
> news:xxxxx@ntdev…
> > > > Hi,
> > > >
> > > > I’m working to develop a Virtual COM Port and i don’t know if the
best
> > > thing
> > > > to do is to create a driver that will connect to serial.sys to send
> the
> > > > requests ? Maybe the best thing is to create a driver that don’t
need
> to
> > > > talk with serial.sys.
> > > >
> > > > Thanks.
> > > >
> > > >
> > > >
> > >
> > >
> > >
> >
> >
> >
>
>
>
(1) Yes using the Virtual Bus idea will work. It is a bit of work. Good
Luck.
Sincerely;
Mike Jones
“Francky” wrote in message news:xxxxx@ntdev…
> It could be interesting to use the Virtual bus driver idea.
> I’ve created a template of Virtual Serial Driver with DriverStudio and
that
> seem to be a good departure.
> I started my driver like you said in your idea #5.
> If you can help me you are .
>
> “Michael Jones” wrote in message
> news:xxxxx@ntdev…
> > (1) I have to respond about doing a filter driver for serial.sys.
> > (2) One this may not work. Here is how I understand what you are trying
> to
> > do. You have more than one process running both opening say COM1: All
> the
> > processes will get the same data on reading from COM1:
> > (3) The other way is by writing a Virtual Bus Driver that creates say
> COM7:
> > COM8: COM9: etc. this you can configure. Each of these can be
exclusive:
> > The Virtual Bus Driver will open say COM1: and then send the same data
to
> > COM7: COM8: COM9: etc. This I know works.
> > (4) You could could also create also create a single Virtual Serial Port
> > Driver that creates a single port say COM7: that opens say COM1: but
allow
> > multiple access on this COM7:
> > (5) You could also create the above Virtual Bus Driver that creates like
> > step (2) above but allows multilple access on the Virtual Com ports
COM7:
> > COM8: COM9:
> > (6) !!! The only one I have done is 3 and I know this works -
why
> > because I have done. All the others are Research and Development.
> > (7) Contact me via email or this list server if I help more. Would love
> to
> > work with you on this. Multiplexing an Exclusive Access Device sounds
> cool.
> >
> > Sincerely;
> > Mike Jones
> >
> >
> >
> > “Francky” wrote in message
news:xxxxx@ntdev…
> > > I will try to do a filter driver that talk with serial.sys.
> > >
> > > Thanks.
> > >
> > >
> > > “Michael Jones” wrote in message
> > > news:xxxxx@ntdev…
> > > > (1) Com ports are exclusive. If you look at the serial driver in the
> ddk
> > > it
> > > > will fail the open request if the port is already open. Plus
changing
> > this
> > > > is not recommended because serial.sys was designed for exclusive
> access.
> > > > (2) You could write a Virtual Com Driver that will open the real
> > > serial.sys
> > > > and pass all the data to all Virtual Com ports that the virtual
driver
> > > > creates. A big task but of course do able. This will have to be a
bus
> > > > driver.
> > > > (3) Trying to be creative you MAY be able to write a filter driver
for
> > the
> > > > serial.sys that could “transform” the serial.sys to allow more than
> one
> > > > process to have say the com port open and to get the reads. This is
> not
> > > > trival.
> > > > (4) Number 2 I know will work I have done something similiar.
Number
> 3
> > I
> > > > just thought of now and I not completely sure.
> > > >
> > > > Sincerely;
> > > > Mike Jones
> > > >
> > > > “Francky” wrote in message
> > news:xxxxx@ntdev…
> > > > > Hi,
> > > > >
> > > > > I’m working to develop a Virtual COM Port and i don’t know if the
> best
> > > > thing
> > > > > to do is to create a driver that will connect to serial.sys to
send
> > the
> > > > > requests ? Maybe the best thing is to create a driver that don’t
> need
> > to
> > > > > talk with serial.sys.
> > > > >
> > > > > Thanks.
> > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > >
> > >
> > >
> >
> >
> >
>
>
>
(1) I can try to answer question when you get stuck. I am busy myself with work to commit.
Sincerely;
Mike Jones
-----Original Message-----
From: Francky
Sent: Jul 29, 2005 4:18 PM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Question about Virtual COM Port
It could be interesting to use the Virtual bus driver idea.
I’ve created a template of Virtual Serial Driver with DriverStudio and that
seem to be a good departure.
I started my driver like you said in your idea #5.
If you can help me you are .
“Michael Jones” wrote in message
news:xxxxx@ntdev…
> (1) I have to respond about doing a filter driver for serial.sys.
> (2) One this may not work. Here is how I understand what you are trying
to
> do. You have more than one process running both opening say COM1: All
the
> processes will get the same data on reading from COM1:
> (3) The other way is by writing a Virtual Bus Driver that creates say
COM7:
> COM8: COM9: etc. this you can configure. Each of these can be exclusive:
> The Virtual Bus Driver will open say COM1: and then send the same data to
> COM7: COM8: COM9: etc. This I know works.
> (4) You could could also create also create a single Virtual Serial Port
> Driver that creates a single port say COM7: that opens say COM1: but allow
> multiple access on this COM7:
> (5) You could also create the above Virtual Bus Driver that creates like
> step (2) above but allows multilple access on the Virtual Com ports COM7:
> COM8: COM9:
> (6) !!! The only one I have done is 3 and I know this works - why
> because I have done. All the others are Research and Development.
> (7) Contact me via email or this list server if I help more. Would love
to
> work with you on this. Multiplexing an Exclusive Access Device sounds
cool.
>
> Sincerely;
> Mike Jones
>
>
>
> “Francky” wrote in message news:xxxxx@ntdev…
> > I will try to do a filter driver that talk with serial.sys.
> >
> > Thanks.
> >
> >
> > “Michael Jones” wrote in message
> > news:xxxxx@ntdev…
> > > (1) Com ports are exclusive. If you look at the serial driver in the
ddk
> > it
> > > will fail the open request if the port is already open. Plus changing
> this
> > > is not recommended because serial.sys was designed for exclusive
access.
> > > (2) You could write a Virtual Com Driver that will open the real
> > serial.sys
> > > and pass all the data to all Virtual Com ports that the virtual driver
> > > creates. A big task but of course do able. This will have to be a bus
> > > driver.
> > > (3) Trying to be creative you MAY be able to write a filter driver for
> the
> > > serial.sys that could “transform” the serial.sys to allow more than
one
> > > process to have say the com port open and to get the reads. This is
not
> > > trival.
> > > (4) Number 2 I know will work I have done something similiar. Number
3
> I
> > > just thought of now and I not completely sure.
> > >
> > > Sincerely;
> > > Mike Jones
> > >
> > > “Francky” wrote in message
> news:xxxxx@ntdev…
> > > > Hi,
> > > >
> > > > I’m working to develop a Virtual COM Port and i don’t know if the
best
> > > thing
> > > > to do is to create a driver that will connect to serial.sys to send
> the
> > > > requests ? Maybe the best thing is to create a driver that don’t
need
> to
> > > > talk with serial.sys.
> > > >
> > > > Thanks.
> > > >
> > > >
> > > >
> > >
> > >
> > >
> >
> >
> >
>
>
>
—
Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256
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