Hitachi SJ700B SERIES, Instruction Manual

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Chapter 4 Explanation of Functions
4 - 128
(3) How to calculate the block check code (BCC)
(Example) When using the 01 command (frequency-setting command) to set the inverter output
frequency to 5 Hz (the station No. of the inverter is 01):
The contents of "Station No." to "Data" are converted into ASCII data, and the ASCII data is XORed bit by
bit. The final XOR result is set as the block check code (BCC). In the above example of transmission frame,
BCC is calculated as follows:
(Reference) ASCII code conversion table
Character data ASCII code Character data ASCII code
STX 2 A 41
ACK 6 B 42
CR 0D C 43
NAK 15 D 44
0 30 E 45
1 31 F 46
2 32 H 48
3 33 P 50
4 34 b 62
5 35
6 36
7 37
8 38
9 39
05 (This result is used as BCC.)
Transmission frame configuration
Station No. Command
Data
ASCII code