Delta EB3000 Series User Manual page 471

Appendix B. Modbus ProtocolEB3000
B-1 Introduction
Modbus, originally published in 1979, is a data communication protocol for connecting between
automation devices. It was developed for industrial applications, and mainly used for transmitting data
through serial data lines. It helps users to control by computers and monitor drive parameters and status
through Modbus by using RS-485 serial communication interface.
When using the communication interface, the diagram on the right
shows the communication port pin definitions. It is recommended that you
connect the AC motor drive to your PC by using Delta IFD6530 or IFD6500
as a communication converter.
The default communication formats for communication port:
Modbus RTU mode

19200 bps serial communication baud rates

8-bit data character

No parity bit

2 stop bit

What is Modbus protocol?
Modbus, a request-response protocol, is made up of master and slave architecture. The master-
and-slave architecture communication always appears in pairs, that is, there must be a device that sends
request and waits for response, and this device (master) is responsible for initiating each
communication. Generally speaking, master device is PLC (Programmable Logic Controller) or PC
(Personal Computer), and slave device is the drive.
Master-Slave Architecture
B-2