When printing copies, PCL and Color PCL printers print the given number of each page (uncollated). To get a number of collated copies, the start and end of the print job (whatever number of pages are in the job) needs to be defined. The HP PJL differentiates this by COPIES as uncollated pages and QTY as the quantity of collated jobs. Laser printers need a job defined to get collated copies working.
Sample HP commands
\x1b%-12345X@PJL JOB NAME = "eFORMz"\r\n@PJL SET QTY=3\r\n@PJL ENTER LANGUAGE = PCL\r\n
\x1b%-12345X@PJL EOJ NAME = "eFORMz"\r\n\x1b%-12345X
Set the header string as a variable. Create in the project with the QYT=3 (number three replaced with needed copies).
Note: Check printer manuals for other brands.