Data Matix C40 encoding

[robwebb]

We are using a product that uses MrvBarDll.dll V3.3 to produce a Mailmark CMDM Data Matrix barcode for some reason the latch to C40 is in the middle of the data string not at the start as required, does anyone know if there is a resolution to this problem? Thanks

[glitch]

I do not understand why you care about the internal encoding. The datamatrix spec says that the encoding mode is taken automatically with the goal to minimize the overall symbol size.

Some competitors' product can only encode under one encoding mode for the whole symbol. Thus they require you to select the encoding mode for the whole symbol. This behavior is not standard compliant.

[robwebb]

Thanks Glitch for your response. I've looked at ISO 16022 and agree with your response. We are trying to produce a data matrix barcode to be compliant with the Royal Mail's Mailmark® barcode definition document, which states that;

"“The Basic C40 character is the data encoding standard (Upper case Alphas, Numerals and the SPACE character only) for 2D CMDMs. All data within the Royal Mail defined portion of the CMDM (all fields except customer content) shall comply with the C40 Basic Character set and C40 encodation scheme as described within ISO 16022 (ie the encoding should commence from the start of the data string”

Is there a way to switch the software to just use C40 encoding and not switch encoding automatically?

Note, All the data characters input into the Barcode are C40 characters (Upper Case Alphas & Numerals and the Space).

Thanks

[glitch]

The fact that all characters in the data string can be encoded in C40 does not mean that C40 is the most efficient. For example, numeric data is best encoded using ASCII encodation, numeric mode. The latter encodes 1 digit into 3.5 bits while C40 encodes 1 digit into 5.33 bits. Furthermore, a datamatrix symbol always starts with ASCII encodation, and switching to C40 incurs a cost. In short, it is not always efficient to use C40 on upper case and numeric strings.

I read the royal Mail mark barcode requirement. It requires the "header" encoded in C40 throughout and the remaining "customer content" in whatever efficient, and uses a unlatch to ASCII in the middle if the second part does not start with C40 encodation. The "customer content" may contain characters that can't be encoded in C40, or not efficiently encoded in C40. To comply with this requirement we will have to change the encoder and the "header" and "customer content" must be passed separately. This can't be achieved by the current software we have.

If you are willing to pay a development fee we can develop this feature. Email support@morovia.com with your requirement and we can give you the approximate cost.

[robwebb]

In this particular case the "customer content" is not required and the content can be always fixed to C40 characters ie AAAAAA.

Could the existing software be Fixed to C40 encoding if the "Customer Content" is always fixed to the same C40 characters?

Thanks

[glitch]

This is not a bug so we can't "fix" it. Forcing encodation mode on part of the data encoded is not defined in the datamatrix standard. We may consider adding the support in the future release.

[glitch]

Royal Mail MailMark barcodes are now supported in DataMatrix Fonts & Encoders 5.1 release. The support is done through enhancing the size ID parameter so no new API is introduced.

Product Page: http://www.morovia.com/fonts/datamatrix/

Manual page: http://www.morovia.com/manuals/datamatr ... php#N11232