Example Messages Modbus/Tcp; 16-Bit Access; Function Code 3, Read 16-Bit Parameter - BONFIGLIOLI Active cube Operation Manual

9

Example messages Modbus/TCP

This chapter describes some examples of telegrams for Modbus/TCP.
9.1

16-bit access

9.1.1

Function code 3, read 16-bit parameter

Example 1:
Reading of parameter
Rated speed
dress 1.
Request: Master  frequency inverter
Field:
Transaction ID
Hex nn nn
Response: Frequency inverter  Master
Field:
Transaction ID
Hex nn nn
The sent hexadecimal value is 0x056E = Decimal 1390. Parameter
places. Thus, the rated speed is 1390 min
Example 2:
Reading of parameters
Rated speed
to 1 and number of registers set to 2 (non-permissible value).
Request: Master  frequency inverter
Field:
Transaction ID
Hex nn nn
Error response: Frequency inverter  Master
Field:
Transaction ID
Hex nn nn
The sent exception condition code is the hexadecimal value 0x04 = ERROR SLAVE DEVICE.
44
372 (0x0174) in data set 2 from the frequency inverter with ad-
MBAP
Protocol ID Length
nn nn 00 06
MBAP
Protocol ID Length
nn nn nn
-1
.
372 (0x0174) in dataset 0 of frequency inverter with address set
MBAP
Protocol ID Length
nn nn 00 06
MBAP
Protocol ID Length
nn nn 00
ACU
Modbus/TCP
Unit Func. DSet/ParNo.
ID
01 03 21
Unit Func. No.
ID Bytes
nn 01 03 02
Rated speed
Unit Func. DSet/ParNo.
ID
01 03 01
Unit Func. Excep.
ID
03 01 83
Number of
registers
74 00 01
Par.value
05 6E
372 has no decimal
Number of
registers
74 00 02
04
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