Re: Cyclic Redundancy Checking (CRC) in RPG

Hi, Robert:

There are many possible polynomial formulas that could be used to create a 16-bit CRC (CRC-16). :-o

So, since you say "This is from their API docs" ... perhaps you should ask this vendor or 3rd party for sample code or pseudo-code or other specifications of exactly what algorithm they are using, and apparently expect you to use? Or, perhaps they provide a callable "API" (routine) that you can call, passing the data buffer, and it returns the computed CRC checksum?

Mark S. Waterbury

> Robert Upshall wrote:

I working with a 3rd party socket interface and it is requiring a CRC with each request I transmit. This is from their API docs:

CRC -16 generating polynomial: X16 + X15 + X13 + 1
Namely the binary value: 1101000000000001

Robert



DeLong, Eric wrote:

Sure, about 15 years ago for a zmodem application... This was somewhat
common when we used dial-up over POTS. What is your application?
If intent is to ensure a transferred file is unchanged, you might be
better off with a standard like MD5 or SHA for checksum hash. Please
note that many communications interfaces make use of CRC algorithms
already, to ensure the integrity of data being transmitted. Also note
that there are dozens of different CRC algorithms, so you must be sure
to clarify the requirements.

-Eric

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Robert Upshall
Sent: Thursday, March 25, 2010 11:29 AM
To: rpg400-l@xxxxxxxxxxxx
Subject: Cyclic Redundancy Checking (CRC) in RPG

Has anybody ever done a Cyclic Redundancy Check (CRC) in RPG?

Robert