EUCHNER HBLS 072725 - Handbuch (Seite 33)

EUCHNER Pendant station HBLS 072725
067018-08-01/06 Subject to technical modifications page 11 / 22
8.2 Character Definition
data format: 8 BIT, value range 0x00 ... 0xFF (00H ... FFH)
The value range has following chapters:
0x00 0x1F : common control characters
0x30 0x3C : push buttons change
0x41 0x4C : selector switch W1 status change
0x51 0x5C : selector switch W2 status change
0x30 0x3C : LED on
0x40 0x4C : LED off
0x50 0x5C : LED flashing
0x20 0x7F : control characters and instructions for the LCD (identified with 0x6C)
0x80....0xFF.: LCD character set (see chapter Character Set )
Control characters:
STX
0x02 Start of Text
Beginning of the character sequence
ETX 0x03 End of Text
End of the character sequence
DLE 0x10 Data Link Escape
Data transfer direction change
NAK 0x15 Negative Acknowledge
BCC 0x00 ... 0xFF Block Check Character
8.3 BCC Block Check Character / equal to 3964R
The BCC (Block Check Character) is generated by calculation.
All the characters in a string have to be exclusive OR’d with each.
The resulted BCC character is added as the final character.
STX
Data Block DLE ETX BCC
calculation:
1. character of the data block
XOR 2. character of the data block
XOR - - -
XOR last character of the data block
XOR DLE
XOR ETX
= BCC
simplification:
The 2 control characters, ETX and DLE are always present. You can collect them
(03 XOR 10 = 13) and calculate the data block separately. The result of the data block is
afterwards exclusive OR’d with the constant value 13H.
BCC = ( XOR Data Block ) XOR ( 13H ).