I have acquired an Epson thermal printer (TM-T82II) with a control utility (APD5) that allows me to configure and test the printer. I use the utility to (try to) print barcodes, but cannot find any documentation on how to make use of the Code128 support I need.
I want to print out a Code 128 barcode for "PQR123X1122331807110011223344". I seem to be able to do this by specifying a test string of "{APQR123X1122331807110011223344" to encode the string in Font A, and likewise use "{BPQR123X1122331807110011223344" to encode it entirely in Font B. Both generate barcodes too wide for the paper I have. However, there is a large run of digits after the "X" which is more efficiently encoded in Font C and that I know will fit (I have an example from another printer). The obvious thing of using "{APQR123X{C1122331807110011223344" produces garbage.
Can anyone point to documentation that unravels how Epson do font-switching in Code 128?