YASKAWA JOHB-SMP3-MA Technical Manual page 34

7 Modbus TCP/IP Messaging
Description
Write Starting Register
Quantity of Registers to Write
Write Byte Count
Write Register Values
*1 M = Quantity of Registers to Read (range is 1 - 16)
*2 N = Quantity of Registers to Write (range is 1 - 16)
Description
Slave Address (Unit Identifier)
Function Code
Number of Data Bytes
Read Register Values
*1 M = Quantity of Registers
Description
Slave Address (Unit Identifier)
Error Code
Exception Code
Read/Write Multiple Registers
Table 7.27 lists command examples when reading registers 0001 (Hex.) and 0002 (Hex.) and then writing register
values 0103 (Hex.) and 0258 (Hex.) to register addresses 0102 (Hex.) and 0103 (Hex.) in a drive with the slave
address (unit identifier) 01 (Hex.).
Table 7.28 shows examples of responses indicating that the read/write multiple registers command has been
executed successfully. Read data 1 contains the value of register address 0001 (Hex.) (0001 (Hex.)). Read data 2
contains the value of the register address 0002 (Hex.) (0002 (Hex.)).
Table 7.29 shows examples of an error response when the command to read and write to multiple registers has
failed. The exception code is 02 (Hex.) (indicating a register number error).
Read Starting Register
Quantity of Registers to Read
Write Starting Register
Quantity of Registers to Write
First Write Register Data
Next Write Register Data
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Table 7.25 Read/Write Multiple Registers Response
Table 7.26 Read/Write Multiple Registers Error Response
Table 7.27 Example Read/Write Multiple Registers Command
Description
Slave Address (Unit Identifier)
Function Code
Write Byte Count
Byte No.
2
2
1
*2
N × 2
Byte No.
1
1
1
*1
M × 2
Byte No.
1
1
1
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
YASKAWA SIEP C730600 0IB Modbus TCP/IP Technical Manual
Data (Hex.)
0000 - FFFF
*2
N
*2
N × 2
0000 - FFFF
Data (Hex.)
00 - FF
17
*1
M × 2
Values contained in slave registers
Data (Hex.)
00 - FF
97
Refer to Modbus TCP/IP Exception Codes.
Data (Hex.)
01
17
00
01
00
02
01
02
00
02
04
01
03
02
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