YASKAWA JOHB-SMP3-MA Technical Manual page 33

Table 7.22 shows examples of responses indicating that the write command has been executed successfully. The
command specifies the beginning of the register address and the number of registers.
Table 7.23 shows examples of an error response when writing to a register. The exception code is 02 (Hex.)
(indicating a register number error).
Starting Register
Quantity of Registers
First Register Data
Next Register Data
*1 This option is set up to use PLC based (holding) register addressing (base 1). The drive will automatically convert the register
address to one more than the address sent over the network before it will respond.
When writing the starting register 0001 (Hex.) from the PLC:
1. The PLC sends out a command specifying the starting register 0000 (Hex.) to the network.
2. The drive automatically convert the starting register 0000 (Hex.) to 0001 (Hex.).
3. The drive responds the value of register address 0001 (Hex.) to the PLC.
Starting Register
Quantity of Registers
Slave Address (Unit Identifier)
Exception Code
23 (17 (Hex.)) Read/Write Multiple Registers
This function code performs a combination of one read operation and one write operation in a single Modbus
TCP/IP transaction. The write operation is performed before the read. The command specifies the starting read
address, quantity of contiguous registers to read, starting write address, quantity of contiguous registers to write
and the values to be written. The normal response contains the values of the registers that were read.
For both the address and the values, the first byte contains the most significant bits and the second byte contains
the least significant bits.
Description
Slave Address (Unit Identifier)
Function Code
Read Starting Register
Quantity of Registers to Read
YASKAWA SIEP C730600 0IB Modbus TCP/IP Technical Manual
Table 7.21 Examples of Multiple Registers Write Command
Description
Slave Address (Unit Identifier)
Function Code
*1
Number of Data Bytes
Table 7.22 Example Write Multiple Registers Response
Description
Slave Address (Unit Identifier)
Function Code
Table 7.23 Example Write Multiple Registers Error Response
Description
Error Code
Table 7.24 Read/Write Multiple Registers Command
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
Upper
Lower
Byte No.
1
1
2
2
7 Modbus TCP/IP Messaging
Data (Hex.)
01
10
00
01
00
02
04
00
01
02
58
Data (Hex.)
01
10
00
01
00
02
Data (Hex.)
01
90
02
Data (Hex.)
00 - FF
17
0000 - FFFF
*1
M
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