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DLL Trail

Hi

I posted last year regarding accessing DLLs from LabVIEW. I've now hit a brick wall after getting the vendor's data sheets.

My main concern at the moment is that the DLL is looking for C variables of the type LONG, SHORT, INT, etc, but when creating the call in the configure window, the preview does not show these variable types. Needless to say, the whole lot crashes the instant I run it.

Is there a look up table showing compatible data types that I can get my hands on?

Any suggestions?

Yours sincerely,
Chris McCrory
Project Engineer
______________________________________________
SP Technology Limited
E-mail: c.mccrory@sp-tech.com
Website: www.sp-tech.com
Tel: +44 (0) 1382-880088
Fax: +44 (0) 1382-880099

The information in this e-mail i
s confidential and for use by the addressee(s) only. If you are not the intended recipient or responsible for delivery of the message to the intended recipient, please notify us immediately on +44 (0) 1382 880088 and delete the message from your computer; you may not copy or forward it, or use or disclose its contents to any other person. As Internet communications are capable of data corruption, SP Technology Ltd do not accept any responsibility for changes made to this message after it was sent. For this reason it may be inappropriate to rely on advice contained in an e-mail without obtaining written confirmation of it. Please note that SP Technology Ltd does not accept the liability or responsibility for viruses and it is your responsibility to scan attachments, if any. Opinions and views expressed in this e-mail are those of the sender and may not reflect the opinions of SP Technology Ltd.
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Message 1 of 4
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Chris McCrory wrote:

> Hi I posted last year regarding accessing DLLs from LabVIEW. I've now hit
> a brick wall after getting the vendor's data sheets. My main concern at
> the moment is that the DLL is looking for C variables of the type LONG,
> SHORT, INT, etc, but when creating the call in the configure window, the
> preview does not show these variable types. Needless to say, the whole lot
> crashes the instant I run it. Is there a look up table showing compatible
> data types that I can get my hands on?
>
Typically INTs are at least 8 bits (can be 16) SHORT 8 bits (can be 16) and
LONGs are 32 bits.
You can look in the Labview docs to see what size they are. The DLL should
follow the convention
of the compiler that made it.
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Message 2 of 4
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For a 32-bit operating system, such as Win9x or NT, usually the
following applies:

long - 4 bytes - 32 bits, use labview I32
short - 2 bytes - 16 bits, use labview I16
int - 4 bytes - 32 bits, use labview I32

for "unsigned" integers (for example: "unsigned long"), use the U32
type, etc.


Also, remember to check if the DLL requires the parameters to be passed
as values or as pointers. Improper pass configuration can also cause a
crash.

Max



In article <93unr3$snd$1@plutonium.btinternet.com>,
"Chris McCrory" wrote:
> This is a multi-part message in MIME format.
>
> ------=_NextPart_000_0026_01C07EE8.6B5021E0
> Content-Type: text/plain;
> charset="iso-8859-1"
> Content-Transfer-Encoding: quoted-printable
>
> Hi
>
> I posted last year regarding accessing DLLs from LabVIEW. I've now
hit a =
> brick wall after getting the vendor's data sheets.
>
> My main concern at the moment is that the DLL is looking for C
variables =
> of the type LONG, SHORT, INT, etc, but when creating the call in the =
> configure window, the preview does not show these variable types. =
> Needless to say, the whole lot crashes the instant I run it.
>
> Is there a look up table showing compatible data types that I can get
my =
> hands on?
>
> Any suggestions?
>
> Yours sincerely,
> Chris McCrory
> Project Engineer
> ______________________________________________
> SP Technology Limited
> E-mail: c.mccrory@sp-tech.com
> Website: www.sp-tech.com
> Tel: +44 (0) 1382-880088
> Fax: +44 (0) 1382-880099
>
> The information in this e-mail is confidential and for use by the =
> addressee(s) only. If you are not the intended recipient or
responsible =
> for delivery of the message to the intended recipient, please notify
us =
> immediately on +44 (0) 1382 880088 and delete the message from your =
> computer; you may not copy or forward it, or use or disclose its =
> contents to any other person. As Internet communications are capable
of =
> data corruption, SP Technology Ltd do not accept any responsibility
for =
> changes made to this message after it was sent. For this reason it
may =
> be inappropriate to rely on advice contained in an e-mail without =
> obtaining written confirmation of it. Please note that SP Technology
=
> Ltd does not accept the liability or responsibility for viruses and
it =
> is your responsibility to scan attachments, if any. Opinions and
views =
> expressed in this e-mail are those of the sender and may not reflect
the =
> opinions of SP Technology Ltd.
>
> ------=_NextPart_000_0026_01C07EE8.6B5021E0
> Content-Type: text/html;
> charset="iso-8859-1"
> Content-Transfer-Encoding: quoted-printable
>
>
>
> > charset=3Diso-8859-1">
>
>
>
>
>
Hi

>
 

>
I posted last year regarding accessing DLLs from =
> LabVIEW. I've=20
> now hit a brick wall after getting the vendor's data =
> sheets.

>
 

>
My main concern at the moment is that the DLL is =
> looking for C=20
> variables of the type LONG, SHORT, INT, etc, but when creating the
call =
> in the=20
> configure window, the preview does not show these variable types. =
> Needless to=20
> say, the whole lot crashes the instant I run it.

>
 

>
Is there a look up table showing compatible data =
> types that I=20
> can get my hands on?

>
 

>
Any suggestions?

>

>

>

>
 

>

>

>

>

>

>

>

>
Yours sincerely,

>
Chris McCrory

>
Project Engineer

>
______________________________________________

>
SP Technology=20
> Limited

>
E-mail: > href=3D"mailto:c.mccrory@sp-tech.com">c.mccrory@sp-
tech.com
=
>
>
Website: > href=3D"http://www.sp-tech.com">www.sp-tech.com

>
Tel: +44 (0) 1382-880088

>
Fax: +44 (0) 1382-880099

>
 

>

>

>

>

>

>
The information in this e-mail is
confidential =
> and for use=20
> by the addressee(s) only. If you are not the intended recipient or =
> responsible=20
> for delivery of the message to the intended recipient, please notify
us=20
> immediately on +44 (0) 1382 880088 and delete the message from your =
> computer;=20
> you may not copy or forward it, or use or disclose its contents to
any =
> other=20
> person. As Internet communications are capable of data corruption, SP
=
> Technology=20
> Ltd do not accept any responsibility for changes made to this message
=
> after it=20
> was sent. For this reason it may be inappropriate to rely on advice =
> contained in=20
> an e-mail without obtaining written confirmation of it.  Please =
> note that=20
> SP Technology Ltd does not accept the liability or responsibility for
=
> viruses=20
> and it is your responsibility to scan attachments, if any. Opinions
and =
> views=20
> expressed in this e-mail are those of the sender and may not reflect
the =
>
> opinions of SP Technology=20
>
Ltd.
D=
>
IV>

>
> ------=_NextPart_000_0026_01C07EE8.6B5021E0--
>
>


Sent via Deja.com
http://www.deja.com/
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Message 3 of 4
(3,023 Views)
also note the calling convention difference between some dll's. Windows
system DLLs are "stdcall" and other dll's may be "C" calling convention.
You will have to look at the header file of the function you are calling to
determine this or try both and the one that doesn't crash is correct.
The difference in calling convention has to do with stack order and who
cleans up the calling stack.

Stu

wrote in message
news:93vr5v$63f$1@nnrp1.deja.com...
> For a 32-bit operating system, such as Win9x or NT, usually the
> following applies:
>
> long - 4 bytes - 32 bits, use labview I32
> short - 2 bytes - 16 bits, use labview I16
> int - 4 bytes - 32 bits, use labview I32
>
> for "unsigned" integers (for example: "unsigned long"), use the U32
> type, etc.
>
>
> Also, remember to check if the DLL requires the parameters to be passed
> as values or as pointers. Improper pass configuration can also cause a
> crash.
>
> Max
>
>
>
> In article <93unr3$snd$1@plutonium.btinternet.com>,
> "Chris McCrory" wrote:
> > This is a multi-part message in MIME format.
> >
> > ------=_NextPart_000_0026_01C07EE8.6B5021E0
> > Content-Type: text/plain;
> > charset="iso-8859-1"
> > Content-Transfer-Encoding: quoted-printable
> >
> > Hi
> >
> > I posted last year regarding accessing DLLs from LabVIEW. I've now
> hit a =
> > brick wall after getting the vendor's data sheets.
> >
> > My main concern at the moment is that the DLL is looking for C
> variables =
> > of the type LONG, SHORT, INT, etc, but when creating the call in the =
> > configure window, the preview does not show these variable types. =
> > Needless to say, the whole lot crashes the instant I run it.
> >
> > Is there a look up table showing compatible data types that I can get
> my =
> > hands on?
> >
> > Any suggestions?
> >
> > Yours sincerely,
> > Chris McCrory
> > Project Engineer
> > ______________________________________________
> > SP Technology Limited
> > E-mail: c.mccrory@sp-tech.com
> > Website: www.sp-tech.com
> > Tel: +44 (0) 1382-880088
> > Fax: +44 (0) 1382-880099
> >
> > The information in this e-mail is confidential and for use by the =
> > addressee(s) only. If you are not the intended recipient or
> responsible =
> > for delivery of the message to the intended recipient, please notify
> us =
> > immediately on +44 (0) 1382 880088 and delete the message from your =
> > computer; you may not copy or forward it, or use or disclose its =
> > contents to any other person. As Internet communications are capable
> of =
> > data corruption, SP Technology Ltd do not accept any responsibility
> for =
> > changes made to this message after it was sent. For this reason it
> may =
> > be inappropriate to rely on advice contained in an e-mail without =
> > obtaining written confirmation of it. Please note that SP Technology
> =
> > Ltd does not accept the liability or responsibility for viruses and
> it =
> > is your responsibility to scan attachments, if any. Opinions and
> views =
> > expressed in this e-mail are those of the sender and may not reflect
> the =
> > opinions of SP Technology Ltd.
> >
> > ------=_NextPart_000_0026_01C07EE8.6B5021E0
> > Content-Type: text/html;
> > charset="iso-8859-1"
> > Content-Transfer-Encoding: quoted-printable
> >
> >
> >
> > > > charset=3Diso-8859-1">
> >
> >
> >
> >
> >
Hi

> >
 

> >
I posted last year regarding accessing DLLs from =
> > LabVIEW. I've=20
> > now hit a brick wall after getting the vendor's data =
> > sheets.

> >
 

> >
My main concern at the moment is that the DLL is =
> > looking for C=20
> > variables of the type LONG, SHORT, INT, etc, but when creating the
> call =
> > in the=20
> > configure window, the preview does not show these variable types. =
> > Needless to=20
> > say, the whole lot crashes the instant I run it.

> >
 

> >
Is there a look up table showing compatible data =
> > types that I=20
> > can get my hands on?

> >
 

> >
Any suggestions?

> >

> >

> >

> >
 

> >

> >

> >

> >

> >

> >

> >

> >
Yours sincerely,

> >
Chris McCrory

> >
Project Engineer

> >
______________________________________________

> >
SP Technology=20
> > Limited

> >
E-mail: > > href=3D"mailto:c.mccrory@sp-tech.com">c.mccrory@sp-
> tech.com
=
> >
> >
Website: > > href=3D"http://www.sp-tech.com">www.sp-tech.com

> >
Tel: +44 (0) 1382-880088

> >
Fax: +44 (0) 1382-880099

> >
 

> >

> >

> >

> >

> >

> >
The information in this e-mail is
> confidential =
> > and for use=20
> > by the addressee(s) only. If you are not the intended recipient or =
> > responsible=20
> > for delivery of the message to the intended recipient, please notify
> us=20
> > immediately on +44 (0) 1382 880088 and delete the message from your =
> > computer;=20
> > you may not copy or forward it, or use or disclose its contents to
> any =
> > other=20
> > person. As Internet communications are capable of data corruption, SP
> =
> > Technology=20
> > Ltd do not accept any responsibility for changes made to this message
> =
> > after it=20
> > was sent. For this reason it may be inappropriate to rely on advice =
> > contained in=20
> > an e-mail without obtaining written confirmation of it.  Please =
> > note that=20
> > SP Technology Ltd does not accept the liability or responsibility for
> =
> > viruses=20
> > and it is your responsibility to scan attachments, if any. Opinions
> and =
> > views=20
> > expressed in this e-mail are those of the sender and may not reflect
> the =
> >
> > opinions of SP Technology=20
> >
> Ltd.
> D=
> >
> IV>

> >
> > ------=_NextPart_000_0026_01C07EE8.6B5021E0--
> >
> >
>
>
> Sent via Deja.com
> http://www.deja.com/
Stu
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