Modbus Message Examples; Modbus Rtu-Message Examples; Bit Parameter Access - BONFIGLIOLI Vectron Agile Communications Manual

9

Modbus Message Examples

This chapter describes some examples for Modbus RTU and Modbus ASCII.
9.1

Modbus RTU-Message Examples

9.1.1

16 Bit Parameter access

9.1.1.1 Function Code 3, Read 16-Bit Parameter
Example 1:
Reading parameter
1.
Request: Master  Frequency Inverter
Field: Addr.
Hex 01
Response: Frequency Inverter  Master
Field: Addr.
Hex 01
The hexadecimal value sent is 0x056E = 1390. Parameter
Therefore, the rated speed is 1390 min
Example 2:
Reading parameter
1 and No. of Regs field set to 2 (invalid value).
Request: Master  Frequency Inverter
Field: Addr.
Hex 01
Error Response: Frequency Inverter  Master
Field: Addr.
Hex 01
The exception code sent is hexadecimal value 0x04 = SLAVE DEVICE FAILURE.
02/2011
Rated Speed
372 (0x0174) in data set 2 from the frequency inverter with address
Func. DSet/Par-No.
03 21 74
Func. No.Bytes Par-Value
03 02 05
-1
.
Rated Speed
372 (0x0174) in data set 0 from the frequency inverter with address
Func. DSet/Par-No.
03 01 74
Func. Except. CRC
83 04 40
No. of Regs CRC
00 01 CE
CRC
6E 3A F8
Rated Speed
No. of Regs CRC
00 02 85
F3
Modbus Agile
2C
372 has no decimal places.
ED
45