Control Techniques UD70 User Manual page 71

The message will be:
Control Address
EOT 1 1 2 2
Not included in the calculation
The first character of the
of which is taken as a starting or result value. The next character is 1 1
(00110001 in binary), which now has the exclusive
upon it. With the previous result value, a new result occurs of 00000001 in
binary.
The complete calculation is show in the table below:
Character
0
1
2
1
–
3
4
.
5
ETX
The final value is the
31 ( characters from 00 to 31 are used as control codes).
ASCII
When the final
In this example, 0011 0000 is 48 decimal which is above 31, so this is the final
value. 48 decimal is the character 0. The complete message will be:
BCC
EOT 1
Example QuickBasic program to calculate
mess$ = CHR$(4)+"1122"+CHR$(2)+"0125"+"-34.5"+CHR$(3)
bcc% = 0
FOR n% = 7 to LEN(mess$)'start at the character after 'chr$(2).
bcc% = bcc% XOR ASC(MID$(mess$, n%, 1))
NEXT
IF bcc% < 32 THEN bcc% = bcc% + 32
mess$ = mess$ + CHR$(bcc%)
PRINT mess$
In , the
DPL
the .
BCC
UD70
Issue code: 70nu2
Control Parameter
STX 0 1 2
Included in the calculation
calculation is 0 0 (00110000 in binary), the value
BCC
Binary Value XOR result
0011 0000 –
0011 0001 0000 0001
0011 0010 0011 0011
0011 0001 0000 0010
0010 1101 0010 1111
0011 0011 0001 1100
0011 0100 0010 1000
0010 1110 0000 0110
0011 0101 0011 0011
0000 0011 0011 0000
provided that its equivalent decimal value exceeds
BCC,
result produces a decimal value less than 32, 32 is added.
XOR
1 2 2 STX 0 1
BCC
and
ANSIREAD ANSIWRITE
Serial communications
Data
1 – 3 4 . 5
( ) operator act
OR XOR
2 1 - 3 4 . 5
functions automatically calculate
Control BCC
ETX 0
Result
ETX 0
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