Using ExtEscape to output data to HP LaserJet p2050 pcl6
I'm having this problem with using ExtEscape to output a segment data to hp laserjet p2050 pcl 6, but the ExtEscape unprovoked outputs "BF FA 22 00 00 00" before i escape my data to the printer. "BF" means "passthrough" operator in the pcl 6, and "FA" is the attribute tag of the dataLength ,"22 00 00 00" is the length of the data that my using ExtEscape to output the printer.
The function call looks like this:
ExtEscape(hDC, PASSTHROUGH, send_len, buf, 0, NULL);
the hDC is printer's device context.
Thanks in advance.