BONFIGLIOLI Active Cube User Manual

7 Protocol
The Modbus/TCP communication protocol is a Client/Server based protocol. Modbus/TCP communica-
tion will always be initialized by the client (e.g. PLC). The server nodes (frequency inverters) do not
communicate with one another.
Modbus/TCP communication will be established by the client via the TCP/IP-Port #502 on the side of
the Modbus/TCP server.
CM
-Modbus/TCP and CM-Modbus/TCP-2P only support
•
Port #502 for establishing Modbus/TCP connection
•
one request per transaction only (NumberMaxOfServerTransaction = 1)
7.1 Telegram structure
A Modbus/TCP telegram comprises the following fields:
MBAP
Function code
Data
(Modbus RTU data contents)
MBAP Modbus Application Header
Field
Length
Description
Client
Server
(inverter)
Transaction ID
(transaction identifier)
2 bytes
Identification of Mod-
bus request/response
transaction
Initialized by
client
Written back by the
server from the
request received
Protocol ID
(protocol identifier)
2 bytes
0 = Modbus protocol
Initialized by
client
Written back by the
server from the
request received
Length
2 bytes
Number of subse-
quent bytes (includ-
ing ID of data unit)
Initialized by
client (request)
Initialized by server
(response)
ID of data unit
(unit identifier)
1 byte
Identification of seri-
ally connected Re-
mote Slave
Initialized by
client (request)
Initialized by server
(response)
•
The data unit identifier will not be processed by the server.
•
The function code and data field structure are the same in Modbus/TCP and Modbus-
RTU.
•
Modbus/TCP uses byte sequence Big-Endian (Motorola format).
The function code tells the server/frequency inverter which action is to be performed. The function
code is followed by a data field containing the parameters of the request (or the response parameters
in the case of the response by the frequency inverter).
If there are no errors while a request is received via Modbus/TCP, the data field will contain the re-
quired data. If an error occurs, the field contains an exception condition code to tell the master that
the request was not processed successfully. For information on how to handle exception conditions
and the exception condition codes, refer to Chapter 7.2.9 “Exception condition codes”.
26
ACU Modbus/TCP 10/13

BONFIGLIOLI Active Cube Specifications

General

Brand	BONFIGLIOLI
Model	Active Cube
Category	Inverter
Language	English

Summary

GENERAL SAFETY INSTRUCTIONS AND INFORMATION ON USE

Designated use

Specifies the inverter's intended design and use in industrial plants and machines.

Misuse

Residual risks

Details hazards that cannot be eliminated despite safety-compliant design, including electrical, thermal risks.

Operator's/operating staff's responsibilities

Organizational measures

Handling and installation

Electrical connections

Safe operation

Outlines safety measures during operation, including cover checks and avoiding unauthorized modifications.

Maintenance and service/troubleshooting

Describes procedures for maintenance, inspections, and repairs, emphasizing qualified personnel.

First commissioning

Assembly/disassembly of communication module

Assembly

Details the process for installing the CM-Modbus/TCP communication module into the frequency inverter.

Disassembly

Modbus/TCP interface

Communication modules

Describes the CM-Modbus/TCP and CM-Modbus/TCP-2P modules and their RJ45 ports.

Setup

Operating behavior in the case of a communication error

Protocol

Supported function codes

Lists Modbus function codes used for reading and writing 16-bit and 32-bit values.

PARAMETER ACCESS

Handling of datasets / cyclic writing of parameters

Handling of index parameters / cyclic writing

EXAMPLE MESSAGES MODBUS/TCP

16-bit access

Provides examples of Modbus/TCP telegrams for reading and writing 16-bit parameters.

32-bit access

Demonstrates Modbus/TCP telegram examples for reading and writing 32-bit parameters.

MOTION CONTROL INTERFACE (MCI) / MOTION CONTROL OVERRIDE (MCO)

Motion Control Override

Functions of Motion Control Interface (MCI)

Covers reference systems, modes of operation, and parameters for MCI.

CONTROL OF FREQUENCY INVERTER

Control via contacts/remote contacts

Details control methods using digital inputs and remote contacts, including status word bits.

Control via state machine

Explains control via the state machine using the control word and status word.

Configurations without Motion Control

Motion control configurations

Explains how motion control configurations use control and status word bits for various modes.

Parameter List

Parameters (Menu “Para”)

Lists all available parameters, their ranges, and related chapters.

APPENDIX

Error messages

Explains error codes, their groups, and meanings for motion control and Ethernet communication.