Daikin DIII EKMBDXB7V1 User Manual

Design guide
Modbus Interface DIII
EKMBDXB7V1

Daikin DIII EKMBDXB7V1 Specifications

General

Category	Air Conditioner Accessories
Model	DIII EKMBDXB7V1
Communication Method	DIII-NET
Product Type	Interface Adapter
Power Supply	DC 12V

Summary

Safety Precautions

1. Introduction

1.1 System layout

Diagram illustrating the typical setup for connecting a BMS to Daikin units via Modbus.

1.2 Limitations

1.3 Specifications

1.3.1 Dimensions and field wiring

Specifies the physical dimensions and wiring requirements for the Modbus Interface DIII.

1.3.2 Wiring diagram

Provides a detailed wiring diagram for connecting the Modbus Interface DIII.

1.3.3 LED meaning

Explains the meaning of the various LED indicators on the Modbus Interface DIII.

1.3.4 Termination resistance (SS switches)

Details how to set the termination resistance using SS switches.

1.3.5 Push buttons

States that push buttons BS1 till BS5 have no assigned meaning.

1.3.6 Dipswitch meaning

Explains the function of dipswitches DS1 and DS2 for configuration.

1.4 Overview of compatible Daikin units ranges with DIII connection

1.5 Overview of compatibility with other DIII centralised control equipment

2. Modbus communication

2.1 Modbus Interface DIII settings

Details Modbus communication settings including protocol, speed, parity, and address.

2.2 Communication format

2.2.1 Function format

Explains the format for Modbus function codes like Read Input Registers.

2.2.2 Character format

Describes the character format for Modbus messages (start bit, data, parity, stop bit).

2.2.3 Silent internal time

Specifies the silent interval time required between Modbus communication frames.

2.2.5 Response time

Defines the response time for the Modbus Interface DIII and master waiting time.

2.3 Communication procedure

2.3.1 System initialisation

Describes the steps for system startup and initialisation of the Modbus Interface DIII.

2.3.2 Monitor and operate units from the BMS

Explains how to monitor and control Daikin units using the BMS via Modbus.

2.3.3 Other DIII devices exist in the same system

Details behavior when other DIII devices are present in the system.

3. Modbus registers

3.1. Input registers

Lists and describes the input registers for status and information of DIII units.

3.2 Holding registers

Lists and describes the holding registers used for controlling Daikin units.

4. Software of Modbus Interface DIII

4.1 Software releases

Information on checking for the latest available software releases.

4.2 Software update with Updater

Instructions for updating the Modbus Interface DIII software using Daikin Updater.

4.2.2 Method 1) Update with the PC USB cable EKPCCAB*

Step-by-step guide for updating software using a USB cable.

4.2.3 Method 2) Update with a USB/RS485 converter.

Step-by-step guide for updating software using a USB/RS485 converter.

5. Modbus Interface DIII test operation

5.1 Introduction

Introduction to testing the Modbus Interface DIII setup with a Modbus master program.

5.2 Outline of system

Diagram of the system setup for testing the Modbus Interface DIII.

5.3 Test Operation Procedure

Guide on how to prepare register groups in the Modbus Poll software.

5.3.2 Start reading registers groups

Instructions for starting to read register groups using Modbus Poll.

5.3.3 Set a holding register

Procedure for changing values in holding registers using Modbus Poll.

6. Troubleshooting

No Modbus communication

Troubleshooting steps for issues related to no Modbus communication.

Software update with updater (via RS485) fails

Troubleshooting steps when software updates via RS485 fail.

A BMS set of a holding register is not reflected on the actual unit.

Troubleshooting for when BMS settings are not reflected on the actual unit.

7. Revision of the document