The Calculate Modulus 10 command calculates the value for a Modulus
10 Self-Check Digit. The command returns a value for the self-check
digit which is intended to be added to a number such as a customer
number. DDS supports the CHECK(M10) keyword for a field to assist in
ensuring the number is keyed correctly.
Self-check digits are commonly used when entering values such as
customer numbers to minimize errors caused by miskeying or
transposing digits.
A different algorithm is required for a UCC modulus 10 self check
digit. See the CLCUCCCHKD tool.
The code for the CLCMOD10 command calculates the self check digit
number by calculating from the units position. This follows the
algorithm used by the system in the CHECK(M10) function in DDS. The
CLCMOD10L command calculates beginning from the high order position.
Both commands produce the same answer on an odd number of digits.
The result differs when there are an even number of digits.
The CLCMOD10 command creates the self-check digit. For example, if
your customer number is 5 digits without the self-check digit, the
following CL program using CLCMOD10 would calculate the self-check
digit and return a 6 digit customer number.
PGM PARM(&CUST5 &CUST6)
DCL &CUST5 *CHAR LEN(5)
DCL &CUST6 *CHAR LEN(6)
DCL &DIGIT *CHAR LEN(1)
CLCMOD10 INPUT(&CUST5) MOD10DGT(&DIGIT)
CHGVAR &CUST6 (&CUST5 *CAT &DIGIT)
ENDPGM
The 6 digit value becomes the customer number.
See the DDS manual for a discussion of how the self-check digit is
calculated.
Checking the value without using DDS
------------------------------------
You can use CLCMOD10 to check a value also. Just strip off and save
the digit position, use CLCMOD10 to calculate the self-check digit,
and them compare the calculated digit to the saved version.
CLCMOD10 algorithm
-------------------
There is a weight factor of 2 for beginning at the units position and
working left every other digit. Each digit of the result is added to
the sum. Then beginning at the units position -1, the sum of the
digits is added.
For example, the number 61248 would result in:
2 x 8 = 16 Digits = 1 and 6 = 7
2 x 2 = 4 Digits = 4 = 4
2 X 6 = 12 Digits = 1 and 2 = 3
--
14
Digits not multiplied 4 and 1 = 5
--
19
Next higher number ending in 0 20
Subtract (20 -19) = 1 as the self check digit
Using CLCMOD10L, the self check digit would be the same because there
are an odd number of digits.
If there is an even number of digits, such as 123456, the result for
CLCMOD10 would be 6.
6 x 2 = 12 Digits 1 + 2 = 3
4 x 2 = 8 Digits 0 + 8 = 8
2 x 2 = 4 Digits 0 + 4 = 4
--
15
Digits 1 + 3 + 5 9
--
24
Next higher number ending in 0 30
Subtract (30 -24) = 6
Using CLCMOD10L, the result would be 9
1 x 2 = 2 Digits 0 + 2 = 2
3 x 2 = 6 Digits 0 + 6 = 6
5 x 2 = 10 Digits 1 + 0 = 1
--
9
Digits 2 + 4 + 6 12
--
21
Next higher number ending in 0 30
Subtract (30 -21) = 9
CLCMOD10 escape messages you can monitor for
---------------------------------------------
TAA9891 The input value cannot be all blanks.
TAA9892 The input value must only contain digits.
Escape messages from based on functions will be re-sent.
CLCMOD10L escape messages you can monitor for
---------------------------------------------
TAA9891 The input value cannot be all blanks.
TAA9892 The input value must only contain digits.
Escape messages from based on functions will be re-sent.
CLCMOD10 Command parameters *CMD
---------------------------
INPUT The input value without the self-check digit. The
value cannot be all blanks and must have only digits
and trailing blanks. Up to 31 digits may be
entered.
MOD10DGT The self-check digit to be returned. The variable
must be declared as *CHAR LEN(1).
CLCMOD10L Command parameters *CMD
----------------------------
INPUT The input value without the self-check digit. The
value cannot be all blanks and must have only digits
and trailing blanks. Up to 31 digits may be
entered.
MOD10DGT The self-check digit to be returned. The variable
must be declared as *CHAR LEN(1).
Restrictions
------------
Because the commands return variables, they may only be used in a CL
program.
Prerequisites
-------------
The following TAA Tools must be on your system:
EDTVAR Edit variable
SNDESCMSG Send escape message
Implementation
--------------
None, the tool is ready to use.
Objects used by the tool
------------------------
Object Type Attribute Src member Src file
------ ---- --------- ---------- ----------
CLCMOD10 *CMD TAACLQZ QATTCMD
CLCMOD10L *CMD TAACLQZ2 QATTCMD
TAACLQZC *PGM CLP TAACLQZC QATTCL
TAACLQZC *PGM CLP TAACLQZC2 QATTCL
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