Why can't I view the check digit of Code 128 in the human readable form?

The MOD103 check digits of the code 128 barcode are not displayed because some of the values go beyond the ASCII character set and cannot be entered from the keyboard. However the check digit may be visible when using the IDAutomation Code 128 Font with one of the Hb fonts provided, such as IDAutomationHbC128s.ttf.

The usual purpose of displaying the check digits in a barcode is to verify data that has been entered manually. If it is necessary to do this, use a barcode that can display the check digits such as Interleaved 2 of 5, Code 39, Code 93 or if encoding numbers only, manually calculate the MOD 10 check digit before the data is sent to the barcode component.

If creating code 128 barcodes and the action calls for a check digit that can be seen in the human readable code as well, it is most likely the software calling for an additional check digit such as a MOD 10 that is used in USPS special services and GS1-128. In these cases, the MOD 10 needs to be calculated before the data is sent to the barcode component.

• UCC/EAN-128 Barcode Information

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