IDEC WB1F Series, User Manual

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2. Installation & wiring 3. Functions 4. Support tool Appendix 1. Overview
5-10
Check digit calculation method
5. 6 Check digit calculation method
RS-232 Type USB Type
A check digit can be added to the output data for readout data and configuration commands.
The check digit is expressed as an 2 digit hexadecimal ASCII code in text.
Calculation range and position where added
The calculation range of the check digit and the position where it is added are as follows.
z
For output data
Add
Calculation range
Global
prefix
Local
prefix
Readout
data
Local
suffix
Check
digit
Global
suffix
z
For configuration commands
Add
Calculation range
Prefix Mnemonic Address
Check
digit
Suffix
Calculation method
All of the ASCII code values for the calculation range are added up, that value is inverted, and 1 is added to it.
Example:
^s1234x118b CR LF
5eH + 73H + 31H + 32H + 33H + 34H + 78H + 31H + 31H = 275H
275H NOT = d8aH
d8aH + 1 = d8bH
d8bH & 0ffH = 08bH
Checksum = 8bH