BONFIGLIOLI Vectron ACTIVE - 8 Modbus Message Examples; Modbus RTU-Message Examples; Function Code 3, Read 16-Bit Parameter

Modbus Instruction manual 05/0838
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Modbus Instruction manual 05/08
8 Modbus Message Examples
8.1 Modbus RTU-Message Examples
8.1.1 Function Code 3, Read 16-bit Parameter
Example 1:
Reading parameter Rated Speed 372 (0x0174) in data set 2 from the frequency
inverter with address 1
Request: Master Î Frequency Inverter
Field: Addr. Func. DSet/Par-No. No. of Regs CRC
Hex
01 03 21 74 00 01 CE 2C
Response: Frequency Inverter Î Master
Field: Addr. Func. No.Bytes Par-Value CRC
Hex
01 03 02 05 6E 3A F8
The hexadecimal value sent is 0x056E = 1390. Parameter
Rated Speed 372 has no
decimal places.
Therefore, the rated speed is 1390 min
-1
.
Example 2:
Reading parameter Rated Speed 372 (0x0174) in data set 0 from the frequency
inverter with address 1 and No. of Regs field set to 2 (invalid value)
Request: Master Î Frequency Inverter
Field: Addr. Func. DSet/Par-No. No. of Regs CRC
Hex
01 03 01 74 00 02 85 ED
Error Response: Frequency Inverter Î Master
Field: Addr. Func. Except. CRC
Hex
01 83 02 C0 F1
The exception code sent is hexadecimal value 0x02 = ILLEGAL DATA ADDRESS.