Firmware revisions 13 and earlier won’t let you enable the Aux port. You have you use a serial K command to enable it and then save for power on <Z>
Here’s a sample K command to enable the Aux port for half duplex <K101,2> is the command- case sensitive then <Z> to save for power on
Firmware Rev 14 is supposed to fix this issue
Zebra software puts a \& in your code when you hit Ctrl M. This may work for other symbologies but not datamatrix. The ZPL manual is very cryptic and I think incorrect. It makes no mention of using the Hex values of the control characters. The underscore character tells ZPL to start an escape sequence.
You must use the Hex value not Decimal. – Carriage Return is 0D so _0D encodes a carriage return in your datamatrix data string.
Here’ a sample string
^FO245,84^BXN,5,200,,,,_^FH^FD12345_0D^FS
