NCR 74 OFX (7874) - ASCII Code; Prefix Byte; RS232 Terminator Byte

Chapter 5: Programming 5-47
TheRS232PrefixByteprogrammingmodecontrolstheuseofprefixbytes.IfanRS232
PrefixByteisused,itistheleadingcharacterineachmessagesenttothehost
terminal.Followingitisthemessagedata.Refertothe“ParameterDefaults”section
earlierinthischapterforthefactory
defineddefaultvalueofeachprogramming
parameter.
Prefix Byte
ThePrefixByteparametercontainstwoselections:DisableandEnable.ScantheHex0
tagtodisablethePrefixByte,ortheHex1tagtoenableit.
ASCII Code
TheASCIICodeparameterpermitsthespecificationofwhatASCIIcodetouseforthe
PrefixByte.EntertheselectionbyscanningtheappropriatetwoHextags(shownin
theASCIICodeChartinProgrammin gchapter).Anyvaluefrom01through0Fcanbe
selected;however,therecommendationistouse
theStartOfText(STX)ASCIICode
whichis02Hex.ScanthetwoappropriateHextags(Hex0throughHex7forthefirst
characterandHex0throughHexFforthesecond).
Note: ASCIICodeparameterfortheRS232TerminatorBytehasthesamefunction.
RS232 Terminator Byte
25786
Terminator Byte 1
A
ASCII Code
B
0
Disable
1
Enable
0 - 7
Hex Character
(ASCII Code Chart)
0 - F
Hex Character
(ASCII Code Chart)
0
Default
3
Your Program
Terminator
Byte 1
A
RS-232
Terminator Byte
2 3
ASCII Code
B
NOTE:
Terminator Byte 1 is required on a
scale unit. If you select
Disable
, it is ignored and an
ETX (03) is sent.
Terminator Byte 2
C
ASCII Code
0
Disable
1
Enable
0 - 7
Hex Character
(ASCII Code Chart)
0 - F
Hex Character
(ASCII Code Chart)
Terminator
Byte 2
C
ASCII Code
0
Default
3
NOTE:
Terminator Byte 2 is a
direct entry only.
