DDSU666 (Direct chint meter ) + mbpoll Command Reference

Version: 1.0
Prepared For: Field & Deployment Teams
Platform: Raspberry Pi / Linux
Tool: mbpoll

1. Purpose

This document explains how to communicate with the CHINT DDSU666 Direct Smart Meter using Modbus RTU and the mbpoll tool.

It covers:
• Reading electrical parameters
• Setting meter addresses
• Verifying communication
• Preparing for OpenEMS integration

2. Hardware & Software Requirements

Hardware
• DDSU666 (Direct Version)
• RS485 → USB Converter
• Raspberry Pi / Linux PC
• Correct RS485 wiring (A↔A, B↔B, GND recommended)

Software
Install mbpoll:

sudo apt update
sudo apt install mbpoll

Check serial port:

ls /dev/ttyUSB*

3. Communication Parameters (Confirmed)

Protocol: Modbus RTU
Baud Rate: 9600
Data Bits: 8
Parity: None
Stop Bits: 2
Format: 8N2
Float Order: Big Endian
Addressing: 0-Based

4. Standard mbpoll Format

mbpoll -m rtu -b 9600 -P none -s 2 -t 4:float -B -0 -r <register> -c <count> /dev/ttyUSB0 -a <id> -1

5. Electrical Parameters

Voltage: 0x2000
Current: 0x2002
Active Power: 0x2004
Power Factor: 0x200A
Frequency: 0x200E
Energy: 0x4000

6. Reading Multiple Values

Use -c option to read multiple registers.

7. Meter Address

Register: 0x0006

8. Changing Address

• Only one meter connected.
• Power cycle after change.

9. Health Check

Voltage should be 220–240V.

10. Common Issues

• Timeout errors
• Wrong wiring
• Duplicate IDs
• Incorrect float order

11. Deployment Workflow

Connect → Configure → Test → Install

12. System Status

✔ Modbus Enabled
✔ 9600 8N2 Confirmed
✔ Big-Endian Floats
✔ Multi-meter Bus Working
✔ Ready for OpenEMS