YASKAWA LA500, Техническое руководство

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Network
Communications
6
6.1 MEMOBUS/Modbus Communications
YASKAWA SIEPYEULA5001C LA500 Technical Manual 141
Table 6.5 CRC-16 Calculation Example
Description Calculation Overflow Description Calculation Overflow
Initial value (FFFF (Hex.)) 1111 1111 1111 1111 - Function code 03 (Hex.) 0000 0011 -
Address 02 (Hex.) 0000 0010 - XOR w result 1000 0001 0011 1101 -
XOR w initial value 1111 1111 1111 1101 Shift 1 0100 0000 1001 1110 1
Shift 1 0111 1111 1111 1110 1 XOR w A001 (Hex.) 1010 0000 0000 0001 -
XOR w A001 (Hex.) 1010 0000 0000 0001 - XOR result 1110 0000 1001 1111 -
XOR result 1101 1111 1111 1111 - Shift 2 0111 0000 0100 1111 1
Shift 2 0110 1111 1111 1111 1 XOR w A001 (Hex.) 1010 0000 0000 0001 -
XOR w A001 (Hex.) 1010 0000 0000 0001 - XOR result 1101 0000 0100 1110 -
XOR result 1100 1111 1111 1110 - Shift 3 0110 1000 0010 0111 0
Shift 3 0110 0111 1111 1111 0 Shift 4 0011 0100 0001 0011 1
Shift 4 0011 0011 1111 1111 1 XOR w A001 (Hex.) 1010 0000 0000 0001 -
XOR w A001 (Hex.) 1010 0000 0000 0001 - XOR result 1001 0100 0001 0010 -
XOR result 1001 0011 1111 1110 - Shift 5 0100 1010 0000 1001 0
Shift 5 0100 1001 1111 1111 0 Shift 6 0010 0101 0000 0100 1
Shift 6 0010 0100 1111 1111 1 XOR w A001 (Hex.) 1010 0000 0000 0001 -
XOR w A001 (Hex.) 1010 0000 0000 0001 - XOR result 1000 0101 0000 0101 -
XOR result 1000 0100 1111 1110 - Shift 7 0100 0010 1000 0010 1
Shift 7 0100 0010 0111 1111 0 XOR w A001 (Hex.) 1010 0000 0000 0001 -
Shift 8 0010 0001 0011 1111 1 XOR result 1110 0010 1000 0011 -
XOR w A001 (Hex.) 1010 0000 0000 0001 - Shift 8 0111 0001 0100 0001 1
XOR result 1000 0001 0011 1110 - XOR w A001 (Hex.) 1010 0000 0000 0001 -
Perform operations with next data (function code)
XOR result 1101 0001 0100 0000 -
CRC-16
1101 0001 0100 0000 -
D 1 4 0
(Lower) (Upper)
-
Continue from here with next data.
Response Data
The drive does the CRC-16 calculation for the response message and makes sure that the data does not have
errors. Make sure that the calculated value is the same value as the CRC-16 in the response message.
◆
Examples of Messages for Commands/Responses
The items in this section are examples of messages for commands/responses.
■
Read Multiple Holding Registers
Uses function code 03 (Hex.) to read the contents of a maximum of 16 holding registers.
Table 6.6 shows example messages when the drive reads status signal from the drive of slave 2, the error contents,
fault contents, and frequency references.
Table 6.6 Message Example When Reading the Contents of Holding Register
Byte Command Message
Setting Data
(Hex.)
Response Message (Normal)
Setting Data
(Hex.)
Response Message (Fault)
Setting Data
(Hex.)
0 Slave address 02 Slave address 02 Slave address 02
1 Function code 03 Function code 03 Function code 83