Brother PT-P900 Reference Manual page 36

Row number 35/36: When transmission is completed, resets bSendRequest (request transmission) and
bStartSend (start transmission).
Row number 38: When bTransExecFlg (under transmission) turns OFF, resets bSetDataFlg (transmission
data set) and increases wPrintCount by one.
Row number 39/40: wPrintCount (print timing counter) is 3 or larger, 0 is stored in wPrintCount (print timing
counter) and bSetDataFlg (transmission data set) is reset.
34
MELSEC iQ-F Brother Label Printer Sample Program Reference Manual