Brother International TD-2020 Raster Command Reference - Page 29

Raster Command Reference (5) Status type Status Type Value Reply to status request 00h Printing completed 01h Error occurred 02h Exit IF mode 03h (not used) Turned off 04h Notification 05h Phase change 06h (Not used) 08h to 20h (Reserved) 21h to FFh If an error occurred during printing, the printer returns the error status. Description (6) Phase type and phase number If the phase number is not used, both are fixed at 00h. Phase State Receiving state Printing state Phase Type 00h 01h Receiving state Phase Waiting to receive Value (Dec.) 0 Higher Order Bytes 00h Lower Order Bytes 00h Printing state Phase Value (Dec.) Higher Order Bytes Lower Order Bytes Printing 0 00h 00h  When the printer is turned on, it is in the receiving state. When printing begins, it changes to the "printing" phase (phase type: printing state; phase number: printing), and the printer sends that phase status to the computer. When printing has finished, the printer sends the "receiving state" phase status (phase type: receiving state; phase number: waiting to receive) to the computer. Unless an error occurs during printing, the printer sends the "printing completed" status.  With concurrent printing, printing starts even if a print command has not been sent from the computer in order to print at high speed. At this time, care should be taken since the "printing" and "waiting to receive" phase statuses will be sent. (Refer to "5. Flow Charts".) - 25 - 4. Printing Command Details