YASKAWA JOHB-SMP3-MA, Technical Manual

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7 Modbus TCP/IP Messaging
30 YASKAWA SIEP C730600 0IB Modbus TCP/IP Technical Manual
Table 7.7 Read Multiple Registers (Response)
Description Byte No. Data (Hex.)
Slave Address (Unit Identifier) 1 00 - FF
Function Code 1 03
Number of Data Bytes 1 2 × N
*1
Register Values N
*1
× 2 Values contained in slave registers
*1 N = Quantity of Registers
Table 7.8 Read Multiple Registers (Error Response)
Description Byte No. Data (Hex.)
Slave Address (Unit Identifier) 1 00 - FF
Error Code 1 83
Exception Code 1 Refer to Modbus TCP/IP Exception Codes.
Examples of Fault Response, Read Response, and Read Multiple Registers Command
Table 7.9 lists command examples to 4 read register contents (register addresses 0020 (Hex.) to 0023 (Hex.)) from
a drive with the slave address (unit identifier) 02 (Hex.).
Table 7.10 shows examples of responses indicating that multiple registers have been read successfully. The
contents read from 0020 (Hex.) are 1770 (Hex.), 1770 (Hex.), 0109 (Hex.), and 0000 (Hex.).
Table 7.11 shows examples of an error response when reading multiple registers. The exception code is 02 (Hex.)
(indicating a register number error).
Table 7.9 Example Read Multiple Registers Command
Description Data (Hex.)
Slave Address (Unit Identifier) 02
Function Code 03
Starting Register
*1
Upper 00
Lower 20
Quantity of Registers
Upper 00
Lower 04
*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 reading the starting register 0020 (Hex.) from the PLC:
1. The PLC sends out a command specifying the starting register 001F (Hex.) to the network.
2. The drive automatically convert the starting register 001F (Hex.) to 0020 (Hex.).
3. The drive responds the value of register address 0020 (Hex.) to the PLC.
Table 7.10 Example Read Multiple Registers Response
Description Data (Hex.)
Slave Address (Unit Identifier) 02
Function Code 03
Number of Data Bytes 08
Starting Register
Upper 17
Lower 70
Next Register
Upper 17
Lower 70
Next Register
Upper 01
Lower 09
Last Register
Upper 00
Lower 00