Hitachi 902 - Frames; Outline of Text

16 - 2
(3) Outline of Text
The format of communication text is shown below.
Each block of text is detailed below.
(a) Start-of-data code (1 character)
STX code (ASCII code $02)
(b) Frame character (1 character)
Refer to Table 16-3.
(c) Data field (variable)
(i) When there is no data field (non-specific request text)
There is no data field because MOR, ANY, REP, SUS and REC are control
frames.
(ii) When there is a data field (specific request text)
Frames other than in (i) above. The data field includes a function character.
(d) End-of-data code (1 to 4 characters)
Any of the following five combinations is selectable on the host setting screen.
(i) ETX + BCC (NOTE 1) ....................................(ASCII code $03 + BCC)
(ii) CR + LF + ETX................................................(ASCII code $0D + $0A + $03)
(iii) ETX.................................................................(ASCII code $03)
(iv) ETX + CR + LF................................................(ASCII code $03 + $0D + $0A)
(v) ETX + CKSH + CKSL (NOTE 2) + CR ............(ASCII code $03 + h + l + $0D)
The text length from (a) to (d) is selectable on the communication parameter screen. (256
or 512 bytes)
Transfer sequence
Start-of-data code (1 character)
Frame character (1 character)
Data field (variable)
End-of-data code (1 to 4 characters)