Winbest DP-Modbus Converter Application Guide for Connecting Siemens S7-300 PLC to Seven‑Segment Display

About this manual

The document describes the hardware wiring of a Winbest DP‑Modbus converter, a Siemens S7‑300 PLC (CPU313C‑2DP) and a customer‑provided seven‑segment display. It includes a connection diagram, USB debugging setup, and the steps to read the display manual for required Modbus commands.

It then explains how to configure the DP‑Modbus module in STEP7: downloading and installing the D_MASTER.GSD file, setting the DP address and baud rate, mapping Modbus registers (address 1, start register 144), and writing PLC data to the display registers. The guide finishes with a sample PLC program and verification of the displayed value (4.90). This manual is written in Chinese.

What's inside

• Introduction and purpose
• Hardware connection diagram
• USB debugging interface
• Modbus command testing with serial assistant
• GSD file download and STEP7 setup
• DP address and baud rate configuration
• Modbus register mapping for the display
• PLC program example and data writing

Specifications

Frequently asked questions

How can I debug the DP‑Modbus module with a PC?

Connect the module’s USB port to the PC, install the USB driver, then use a serial‑assistant program or ModbusPoll to send and monitor Modbus commands.

Which GSD file is required for STEP7 configuration?

Download the D_MASTER.GSD file from Winbest’s website and copy it to the Step7\S7data\gsd\ directory.