How can I compute the 8-bit CRC sum check within an Net Express/VC COBOL program?

Hello,

In my case, I prefer the routine in native code.

I searched the RM-Cobol forum and found a sample file crc32.zip.

Thank you.

 

I wasn't sure if your last reply here meant that you already had a solution to your question but the following is a translation to COBOL of the C program you attached. I don't know much about CRC so cannot guarantee the validity of the program functionality but here is the conversion anyway.

Calling Program:

identification division. program-id. mainprog. data division. working-storage section. 01 input-str pic x(10) value "ABCDEFGHIJ". 01 num-bytes binary-long value 10. 01 crc binary-char unsigned value zeroes. procedure division. call "crc8" using input-str num-bytes crc display crc goback.

CRC subprogram:

$set sourceformat"variable" identification division. program-id. crc-8. data division. working-storage section. 78 CRC-START-8 value 0. 01 sht75-crc-table binary-char unsigned occurs 256 values 0, 49, 98, 83, 196, 245, 166, 151, 185, 136, 219, 234, 125, 76, 31, 46, 67, 114, 33, 16, 135, 182, 229, 212, 250, 203, 152, 169, 62, 15, 92, 109, 134, 183, 228, 213, 66, 115, 32, 17, 63, 14, 93, 108, 251, 202, 153, 168, 197, 244, 167, 150, 1, 48, 99, 82, 124, 77, 30, 47, 184, 137, 218, 235, 61, 12, 95, 110, 249, 200, 155, 170, 132, 181, 230, 215, 64, 113, 34, 19, 126, 79, 28, 45, 186, 139, 216, 233, 199, 246, 165, 148, 3, 50, 97, 80, 187, 138, 217, 232, 127, 78, 29, 44, 2, 51, 96, 81, 198, 247, 164, 149, 248, 201, 154, 171, 60, 13, 94, 111, 65, 112, 35, 18, 133, 180, 231, 214, 122, 75, 24, 41, 190, 143, 220, 237, 195, 242, 161, 144, 7, 54, 101, 84, 57, 8, 91, 106, 253, 204, 159, 174, 128, 177, 226, 211, 68, 117, 38, 23, 252, 205, 158, 175, 56, 9, 90, 107, 69, 116, 39, 22, 129, 176, 227, 210, 191, 142, 221, 236, 123, 74, 25, 40, 6, 55, 100, 85, 194, 243, 160, 145, 71, 118, 37, 20, 131, 178, 225, 208, 254, 207, 156, 173, 58, 11, 88, 105, 4, 53, 102, 87, 192, 241, 162, 147, 189, 140, 223, 238, 121, 72, 27, 42, 193, 240, 163, 146, 5, 52, 103, 86, 120, 73, 26, 43, 188, 141, 222, 239, 130, 179, 224, 209, 70, 119, 36, 21, 59, 10, 89, 104, 255, 206, 157, 172. 01 char-pos binary-long value 0. 01 input-str-hold pic x. 01 input-str-b binary-char unsigned redefines input-str-hold. linkage section. 01 input-str pic x. *> this will actually be num-bytes in length 01 num-bytes binary-long. 01 crc binary-char unsigned. *> This will be the return value procedure division using input-str num-bytes crc. move CRC-START-8 to crc perform varying char-pos from 1 by 1 until char-pos > num-bytes move input-str(char-pos:1) to input-str-hold compute crc = sht75-crc-table(input-str-b b-xor crc) end-perform goback.

Hello, 

In principle, yes, thank you very much.
I have had to adapt the source program a bit, to which I attach, to try it with different strings. And I see that the value of crc-8 is always the same, I do not know if the program is correct.

 

For example:

 

*01 input-str pic x(36) value
* "TBAI-00000006Y-251019-btFpwP8dcLGAF-". .
*01 num-bytes binary-long value 36.
*01 crc binary-char unsigned value zeroes.

ccrc8.  CALL "crc8" USING input-str num-bytes crc.

Can you confirm me if it is correct?

 

 

 

I tested your version of the program and it worked fine. If I change the input string value then the return value will be a different value. What values do you see being returned?

I tested under Visual COBOL 6.0.

Hello,

 

In my case, varying the characters of the 36 position string, the result is always the same: crc = 544.

I have tried it with VC 60 and with NetExpress, and crc = 544.

On the other hand, debugging the program crc8.cbl, in VC 6.0, I find it complicated, examine and monitor the crc field, while in NetExpress, it seems simpler, passing the mouse over the field, it does it by default, and pressing the right button, you have the option to change, monitor it.

 

How should I configure the editor in VCVS2019, so that it behaves in a similar way to NE?

Reading the help in
https://www.microfocus.com/documentation/visual-cobol/vc60/VS2019/GUID-C4313D85-8CD0-47AE-9154-E09DCE81FA0D.html
Pressing Shift F9 , Examine data item' on VC60, shows nothing.

Translated with www.DeepL.com/Translator (free version)

Visual COBOL should allow you to hover the mouse over the data item and it should display in a popup. You can edit the value in place. You can also right click on a data item and select Watch to place it in a watch list.

Something appears to be wrong with your project.

Can you please zip up the solution/project folder and attach it to this post or email it to chris.glazier@microfocus.com?

Thanks