Modbus Communication
‑17‑
2 Modbus Communication
2.1 Communication Overview
The AC drive is provided with RS485 communication interfaces and can serve as a
communication slave in a PC/PLC control network that includes one master and
multiple slaves. You can use a computer or PLC to implement centralized control,
such as setting operation commands, modifying or reading parameters, and reading
running state and fault information of the AC drive.
The AC drive supports the Modbus‑RTU slave communication protocol. This protocol
defines the content and format of messages transmitted during serial
communication. If an error occurs when the slave receives a message, or the slave
cannot complete the action required by the master, the slave returns a fault message
as a response to the master.
2.2 Networking and Interfaces
In a network consisting of one master and multiple slaves, one device is the master (a
PC, PLC, or HMI) and initiates communication to perform parameter read or write
operations on slaves, whereas other devices (slaves) respond to queries or operations
from the master. Only one device is allowed to transmit data at a time, whereas other
devices should be in data receiving status.
Each communication slave has a unique slave address. The address range of the
slaves is 1 to 247, and 0 is a broadcast address.
Communication Networking
Figure 2‑1 Modbus communication networking
Communication Interface
Modbus communication connection is implemented through the CN1 interfaces on
the power supply unit that include one pair of RJ485 terminals, as shown below.
To Next Page
Loading...
Need help?
General