Crc Util

[rda]

I am looking for a crc vi that can process a file and generate
a crc value.
The vi at ftp://ftp.pica.army.mil/pub/labview/vi/lv4/icrc32.zip
does exactly what I what but seems to produce a crc value that does
no match all the other crc utils (Dos based & Windows Based)

For example the Crc of a my command.com is 5C0F32DA using normal window
and dos programs

But when I use the vi indicated above I get a value of 38F8A362

I am Resetting the vi first and calling it using the calculate function

As I don't understand how the crc function works, can anyone explain
how it works and what is the formula for the calculation.

regards
rda

[Johannes Niess]

rda writes:

> I am looking for a crc vi that can process a file and generate
> a crc value.
> The vi at ftp://ftp.pica.army.mil/pub/labview/vi/lv4/icrc32.zip
> does exactly what I what but seems to produce a crc value that does
> no match all the other crc utils (Dos based & Windows Based)
>
> For example the Crc of a my command.com is 5C0F32DA using normal window
> and dos programs
>
> But when I use the vi indicated above I get a value of 38F8A362
>
> I am Resetting the vi first and calling it using the calculate function
>
> As I don't understand how the crc function works, can anyone explain
> how it works and what is the formula for the calculation.
>
> regards
> rda

AFAIK labview has its own byte ordering. I'm messing big/little en
dian
up all the time, but Labview has inherited the one from the Mac, that
is not used on Intel's.

Perhaps you need to swap bytes/words from the advanced function section.

Johannes Nieß

[rda]

Johannes Niess wrote:

> AFAIK labview has its own byte ordering. I'm messing big/little endian
> up all the time, but Labview has inherited the one from the Mac, that
> is not used on Intel's.
>
> Perhaps you need to swap bytes/words from the advanced function section.
>

Thanks for the quick reply.
Do you know of any material I can read up on that would help me
understand the crc function ?
regards
rda

[Geosphere]

I once wrote a function that generates CRC strings. If you want it, you can
ask it on my E-mail address:
Koen.Hoogstoel@ni.com

rda wrote in message
news:3883A2AA.F858721F@subdimension.com...
>

[Rick Nelson]

I wrote a CRC utility in VHDL, and used this as a guide:

ftp://ftp.rocksoft.com/clients/rocksoft/papers/crc_v3.txt

It helped me out a lot! I'll attach the .txt file to this post.


Rick
rick@csciences.com

Chesapeake Sciences Corp.
1127B Benfield Blvd Millersville, MD 21108

Tel: (410) 923-1300 x3430 Fax: (410) 923-2669

[Ed]

A colleage and I collaborated on a CRC generator using HP VEE to communicate with a MODBUS device. I've got some info that may help. If you still need info e-mail me at eshaw@comtechefdata.com

[janderja]

I went to the link and it gave me an error.