32 User’s / Programming GuideBeeper Off CR-LF AckIf the scanner receives an unknown or improperly formatted code, orif the required parameters are missing or out-of-range, it sends aNAK (15H) Code.Serial Commands to Use with CautionSome of the commands in this manual should not be used as serialcommands because of the consequences they produce. All PSC scan-ners use the same hardware components to implement both serialcommunication and wand emulation. This means that all serial com-munication functions are disabled during wand emulation, and viceversa. Because of this, issuing any of the commands in Table 5 causesthe scanner to enter its Wand Emulation mode, thereby disablingserial communication.Furthermore, because the scanner acts upon a command and thensends ACK or NAK, neither or these codes will be transmitted inresponse to any of the above commands. In Table 5 only the com-mand letters are listed; the complete command is prefixed with STXESC, and suffixed with ETX. Because it is not possible to set (via serialcommand) two Wand Emulation parameters (emulation speed andpolarity, for example), scanners to be used in Wand Emulation envi-ronments must be programmed by scanning labels from this manual.Command FunctionSTX ESC PC ETX Enable I 2 of 5 with check digitSTX ESC PD12 ETX Set I 2 of 5 minimum length to 12STX ESC PE14 ETX Set I 2 of 5 maximum length to 12STX ESC KB31323334 ETX Set Preamble to ‘1234’STX ESC LB61626364 Set Postamble to ‘abcd’CB Wand Emulation, Code 39 OutputCC Wand Emulation, Same Code Output