Programming Your 7890 ScannerRS-232 Prefix Byte5-82 User’s GuideRS-232 Prefix ByteThe RS-232 Prefix Byte Programming mode controls theuse of prefix bytes. If you use an RS-232 Prefix Byte, it isthe leading character in each message sent to the hostterminal or PC. Following it is the message data thatmay include a message VLI as its first byte. Refer to theRS-232 Prefix Byte worksheet in Appendix A.The Prefix Byte parameter contains two selections:Disable and Enable. Scan the Hex 0 tag to disable thePrefix Byte, or the Hex 1 tag to enable it. The default isDisable.The ASCII Code parameter permits you to specify whatASCII code to use for the Prefix Byte. Enter yourselection by scanning the appropriate two Hex tags.Refer to the ASCII Code Chart in Appendix A. You canselect any value form 01 through 0F; however, therecommendation is that you use the Start Of Text (STX)ASCII Code which is 02 Hex. Scan the two appropriateHex tags (Hex 0 through Hex 7 for the first characterand Hex 0 through Hex F for the second) The defaultfor this parameter is 02.The RS-232 Prefix Byte Programming mode contains 2shortcuts: A and B. After entering this programmingmode you can go directly to a specific parameter byscanning the appropriate shortcut Hex tag (Hex A orHex B). This eliminates the need to enter all parameterswhen only one needs changing.Prefix ByteASCII CodeParameter Shortcuts
