The ZPL II language documentation contains the command "~ JA", which allows you to clear all jobs in the buffer.
Unfortunately, it does not seem to work on the Zebra GK420d (but I cannot find a word about it in the printer specification).
I can print shortcuts with sending, for example, this line to the printer:
PUT
"^XA" SKIP
"^MMT" SKIP
"^LL1279" SKIP
"^PW799" SKIP
"^LS0" SKIP
"^BY5,3,387^FT633,947^B2B,400,Y,N,Y" SKIP
"^FD>:" v_value FORMAT 'x(8)' "^FS" SKIP
"^FT133,707^A0B,56,81^FH\^FD" v_value "^FS" SKIP
"^FT131,1100^A0B,56,81^FH\^FDVALUE:^FS" SKIP
"^PQ1,0,1,Y^XZ"
SKIP.
Then, if the buffer contains more than two labels, I try to clear the buffer with
PUT
"^XA" SKIP
"~JA" SKIP
"^XZ" SKIP
.
No result.
I also tried PUT "~ JA" SKIP.
Again without result.
I cannot find any information why it does not work or how it works with the Zebra GX420d.
Can you help me? Perhaps this is not possible with this printer.
Thanks for the help.
Best regards, Wiktor