User`s manual

Directions for use
7-17
7
Command content
Sumcheck area
?
(H) (L)(H) (L)
C
R
A
D
A
D
S
C
S
C
Sumcheck code SC (H), SC (L)
The communication port detects error using sumcheck as well as party check in order to increase the
reliability.
11
11
1 Sumcheck area (See page 7-15)
[Example] Command
22
22
2 Check method
1. Add data from station No. to the last data of the command contents or response contents
(just before sumcheck code) that are summed up in ASCII code.
2. Convert the sumcheck code (2 digits hexadecimal) to 8 bits data and add 1 to the result.
When the grand total is "0" (disregarded figure up), the message is regarded as correct,
when the grand total is not "0," the message is regarded as an error.
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3 Produce method
1. Add data from station No. to the last data of the command contents or response contents
(just before sumcheck code) that are summed up in ASCII code.
2. Operate complement number of 2 of the result of 1.
Complement number of 2: Turn over all the bits indicated by the binary system (0 to 1, 1 to 0)
and add 1.
[Example] The complement number of 2 of 4E
HEX
is B2
HEX
4E
HEX
→ 01001110
↓ invert each bit
10110001
↓ add 1
10110010 → B2
HEX
3. Divide upper 4 bits and lower 4 bits and convert them to ASCII code.
When sumcheck is not necessary, setting @ in the command line.