Daikin EKMBDXB7V1 Installer reference guide

Design guide

Modbus Interface DIII

EKMBDXB7V1

Design guide Modbus Interface DIII EKMBDXB7V1

Table of Contents
Safety Precautions ..............................................................................................................................................	3
1. Introduction....................................................................................................................................................	3
1.1 System layout ...........................................................................................................................................	3
1.2 Limitations ................................................................................................................................................	4
1.3 Specifications ............................................................................................................................................	4
1.3.1 Dimensions and field wiring ..............................................................................................................	5
1.3.2 Wiring diagram ..................................................................................................................................	6
1.3.3 LED meaning ......................................................................................................................................	6
1.3.4 Termination resistance (SS switches) ................................................................................................	6
1.3.5 Push buttons......................................................................................................................................	7
1.3.6 Dipswitch meaning ............................................................................................................................	7
1.4 Overview of compatible Daikin units ranges with DIII connection...........................................................	8
1.5 Overview of compatibilty with other DIII centralised control equipment................................................	8
2. Modbus communication...............................................................................................................................	10
2.1 Modbus Interface DIII settings................................................................................................................	10
2.2 Communication format ..........................................................................................................................	11
2.2.1 Function format ...............................................................................................................................	11
2.2.2 Character format .............................................................................................................................	14
2.2.3 Silent internal time ..........................................................................................................................	14
2.2.5 Response time .................................................................................................................................	14
2.3 Communication procedure.....................................................................................................................	15
2.3.1 System initialisation.........................................................................................................................	15
2.3.2 Monitor and operate units from the BMS .......................................................................................	16
2.3.3 Other DIII devices exist in the same system ....................................................................................	20
3. Modbus registers ..........................................................................................................................................	21
3.1. Input registers........................................................................................................................................	21
3.2 Holding registers.....................................................................................................................................	32
4. Software of Modbus Interface DIII ...............................................................................................................	40
4.1 Software releases ...................................................................................................................................	40
4.2 Software update with Updater...............................................................................................................	40
4.2.1 Updater............................................................................................................................................	40
4.2.2 Method 1) Update with the PC USB cable EKPCCAB*. ....................................................................	41
4.2.3 Method 2) Update with a USB/RS485 converter.............................................................................	43
5. Modbus Interface DIII test operation ...........................................................................................................	45
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5.1	Introduction............................................................................................................................................	45
5.2	Outline of system....................................................................................................................................	45
5.3 Test Operation Procedure ......................................................................................................................		46
5.3.1 Prepare register groups ...................................................................................................................		46
5.3.2 Start reading registers groups .........................................................................................................		49
5.3.3 Set a holding register .......................................................................................................................		50
6. Troubleshooting............................................................................................................................................		51
7. Revision of the document.............................................................................................................................		52

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DIII address functions

1-00

1-01

…

Safety Precautions

Before performing design, construction, or maintenance thoroughly, read the “Safety Precautions” in the installation manual provided with the product.

1. Introduction

A Building Manangement System (BMS) can control Daikin units through the Modbus protocol by using the

Modbus Interface DIII EKMBDXB7V1.

Glossary:

-BMS: Building Management System

-DIII unit: Unit with DIII communication connected to the Modbus Interface DIII.

-DIII device: A centralised device from Daikin with DIII communication (e.g. iTM, …)

-Indoor unit: As the main target is to monitor and control VRV connected indoor units, the DIII units are referred to as indoor units. For some systems the connected DIII units are in reality outdoor units (e.g. Applied units)

1.1 System layout

Typical setup (e.g. VRV)

BMS	RS485 Modbus protocol							DIII indoor
	RS485 Modbus protocol							DIII indoor
	2 wire, max wire length 500m							connection

		Outdoor
				Indoor		Indoor		Indoor

Modbus Interface DIII			1-00		1-01		1-02		DIII address
			1-00		1-01		1-02		DIII address


		Outdoor
One Modbus slave
One Modbus slave				Indoor		Indoor		Indoor
address				Indoor		Indoor		Indoor
address
(e.g. 1)
	1-03				1-04		1-05		DIII address
DIII outdoor
connection

DIII address (Group NO) needs to be set on an individual indoor unit or group by the connected userinterface. Functions of each Indoor unit in a range for each register:

Example:

31001 – 31003

31004 - 31006

…

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1.2 Limitations

The number of control commands per indoor unit is limited to 7000 per year.

If the BMS controls the units by using an automatic control program, please make sure it doesn’t exceed this limitation.

1.3 Specifications

Daikin equipment connection	DIII net (F1F2)
	maximum 64 indoor units (groups) and maximum 10 outdoors (addr 1-00 till 4-15)
BMS equipment protocol	Modbus RS485 (2 wire, max 500m)
Installation place	Indoor installation
Operation condition	Temp range 0 till 60°C
Dimensions	379 x 87 x 124 mm
Mass (Weight)	2,1 kg
Power supply	220 – 240 VAC 50 Hz

Software	The Modbus Interface DIII software can be updated with the Daikin Updater PC software
	Refer to chapter “4.2 Software update with Updater” for details.

Installation manual	Provided with the option
Design guide	Latest version available on:
	http://www.daikineurope.com/support-and-manuals/product-information

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1.3.1 Dimensions and field wiring

Refer to installation manual

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Daikin EKMBDXB7V1 Installer reference guide

1.3.2 Wiring diagram

1.3.3 LED meaning

During normal operation (application is running):

H1P: DIII communication (sent)

H2P: DIII communication (receive)

H3P: RS485 communication (sent)

H4P: RS485 communication (receive)

H5P H6P H7P: no meaning

HAP: blinking at 400ms = application is running

During uploading of new software (firmware is running)

H1P till H7P: Progress indication (0 till 100%)

HAP: blinking at 200ms = firmware is running.

1.3.4 Termination resistance (SS switches)

By factory default the termination resistance is 0 Ohm (SS2=Off & SS3 =Off)

SS2 On = 120 Ohm

SS3 On = 100 Ohm

(SS2 = On & SS3 = On, not allowed)

Please slide the SS2 or SS3 to the ON position to set required termination resistance value of the RS485 line.

Remark: SS1: not used.

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1.3.5 Push buttons

BS1 till BS5 have no meaning

1.3.6 Dipswitch meaning

Attention: Dipswitch on/off status is detected during power on of the PCB only. A power reset is needed after setting the switches.

Dipswitch DS1 & DS2 setting:

RS485 Modbus communication speed

DS1 pin 2:Off	9600 bps
DS1 pin 2:On	19200 bps
Modbus communication parity / stop bit
DS1 pin 3:Off 4:Off	Even 1 stop bit
DS1 pin 3:Off 4: On	Odd 1 stop bit
DS1 pin 3:On 4:Off	None 2 stop bit
DS1 pin 3:On 4:On	None 1 stop bit
Modbus address setting
DS2 pin 1/2/3/4	When Modbus address is set (eg 1..15), then modbus RS485 communication is
	enabled.
Off/Off/Off/Off	No Modbus address is set, meaning no modbus RS485 communication
Off/Off/Off/On	Address 1
Off/Off/On/Off	Address 2
…
On/On/On/On	Address 15

Attention:

During software upload with updater PC program via RS485 port a specific dipswitch setting is required. Refer to chapter “4.2.3 Method 2) Update with a USB/RS485 converter.” for details.

Remark: DS1 – pin 1: not used.

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1.4 Overview of compatible Daikin units ranges with DIII connection

For compatibility with a specific model, please check the manual of the corresponding model. Updates of the software will be available on the Business Portal (maintenance by Service)).

Product overview:

•SKY (F1,F2)

•VRV (F1,F2)

•RA (via KRP928)

•VAM / VKM

•EKVDX

•VRV Hydro Box

•Air curtains

•ERQ-Control box (connection to 3rd party AHU)

•Heating

•Applied

1.5Overview of compatibilty with other DIII centralised control equipment

		<![if ! IE]> <![endif]>Intelligent TouchManager	<![if ! IE]> <![endif]>Interface for use inLonWorks®	<![if ! IE]> <![endif]>Interface for use inBACnet®	<![if ! IE]> <![endif]>Intelligent TouchController	<![if ! IE]> <![endif]>Intelligent TabletController	<![if ! IE]> <![endif]>Residential central remotecontroller	<![if ! IE]> <![endif]>Central Remotecontroller	<![if ! IE]> <![endif]>Unified ON/OFFcontroller	<![if ! IE]> <![endif]>Scheduletimer (*1)

		<![if ! IE]> <![endif]>DCM601A51	<![if ! IE]> <![endif]>DMS504B51	<![if ! IE]> <![endif]>DMS502B51	<![if ! IE]> <![endif]>DCS601C51	<![if ! IE]> <![endif]>DCC601A51	<![if ! IE]> <![endif]>DCS303A51	<![if ! IE]> <![endif]>DCS302CA61	<![if ! IE]> <![endif]>DCS301BA61	<![if ! IE]> <![endif]>DST301BA61

DIII Modbus
interface	EKMBDXB7V1	OK	NG	NG	OK	NG	NG	OK	OK	NG

(*1): The schedule timer should be used in combination with the central remote controller or unified ON/OFF controller

•If using in combination with centralized control equipment, the relation between both central remote controllers is last command priority.

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•if using in combination with centralized control equipment, the remote control mode is decided by the setting of the highest priority item in the priority rank.

Priority ranking of Modbus Interface DIII:

No priority ranking is implemented. Meaning, in case another D-BACS device is detected, the lock button & force OFF functions are not available.

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2. Modbus communication

2.1 Modbus Interface DIII settings

Communication protocol	Modbus RTU		Dipswitch setting
	(according to “Modicon Modbus Protocol reference guide” PI-
	MBUS-300 Rev J)
Communication speed	9600 bps		DS1 pin 2:Off
	Or 19200 bps		DS1 pin 2:On
Parity / stop bit	Even 1 stop bit		DS1 pin 3:Off 4:Off
	Odd 1 stop bit		DS1 pin 3:Off 4: On
	None 2 stop bit		DS1 pin 3:On 4:Off
	None 1 stop bit		DS1 pin 3:On 4:On
One dedicated modbus	1..15		DS2 pin 1/2/3/4
address setting			Addr 1: Off/Off/Off/On
			Addr 2: Off/Off/On/Off
			…
			Addr 15: On/On/On/On
Implemented function codes	0x03	Read Holding Registers (broadcast support)
	0x04	Read Input Registers (broadcast support)
	0x06	Preset Single Registers (No broadcast support)
	0x10	Preset Multiple Registers (No broadcast support)
	(remark: Holding Registers will not reflect the actual value)
	(other function codes are treated as illegal function and
	return an exception response)
Data types	Input Register:
	Length 16 bits, Address range: 30001 - 39999
	Holding Register
	Length 16 bits, Address range: 40001 – 49999
	(Data larger than 16 bits can be handled by assigning
	continuous addresses to registers.)
Register addresses	Same address meaning for each applicable model

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2.2 Communication format

2.2.1 Function format

(1) Read Input Registers (0x04) [Function]

Read values of input registers. The address and the content of input registers are described in 3. Modbus registers

[Query]

The query message specifies the start address of the register and the number of registers. The register address starts at zero: register 30001 is addressed as 0.

This function can read up to 32 registers in one query.

Here is an example of a request to slave address 1 for reading 3 register values starting from register 31001.

Query

Field	Data
Slave Address	0x01
Function Code	0x04
Start Address(Upper)	0x03
Start Address(Lower)	0xE8
Number of Registers(Upper)	0x00
Number of Registers(Lower)	0x03
Error Check CRC16(Lower)	0x30
Error Check CRC16(Upper)	0x7B

Response

Field	Data
Slave Address	0x01
Function Code	0x04
Data Size(Bytes)	0x06
Data1(Upper)	0xXX
Data1(Lower)	0xXX
Data2(Upper)	0xXX
Data2(Lower)	0xXX
Data3(Upper)	0xXX
Data3(Lower)	0xXX
Error Check CRC16(Lower)	0xXX
Error Check CRC16(Upper)	0xXX

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(2) Preset Single Register (0x06) [Function]

Write a value to a holding register. In case of broadcast, the value is written to the same holding register of all slave units. The address and the content of the holding registers are described in

3. Modbus registers

[Query]

The query message specifies the start address of the register and a value. The register address starts at zero: register 40001 is addressed as 0. Here is an example of a request to slave address 1 for writing the value ‘2’ to register 42002.

Query

Field	Data
Slave Address	0x01
Function Code	0x06
Address(Upper)	0x07
Address(Lower)	0xD1
Value(Upper)	0x00
Value (Lower)	0x02
Error Check CRC16(Lower)	0x59
Error Check CRC16(Upper)	0x46

Response

Field	Data
Slave Address	0x01
Function Code	0x06
Address(Upper)	0x07
Address(Lower)	0xD1
Value(Upper)	0x00
Value (Lower)	0x02
Error Check CRC16(Lower)	0x59
Error Check CRC16(Upper)	0x46

(3) Preset Multiple Registers (0x10) [Function]

Write values to holding registers. In case of broadcast, the values are written to the same holding registers of all slave units. The address and the content of holding registers are described in

3. Modbus registers

[Query]

The query message specifies the start address of the register, size of data and values. The register address starts at zero: register 40001 is addressed as 0. This function can write up to 30 registers in one query. Here is an example of a request to slave address 1 for writing 2 values to register 42001 and to register 42002.

Query

Field	Data
Slave Address	0x01
Function Code	0x10
Start Address(Upper)	0x07
Start Address(Lower)	0xD0
Number of Registers(Upper)	0x00
Number of Registers(Lower)	0x02
Data Size(bytes)	0x04
Value1(Upper)	0x00
Value1(Lower)	0x10
Value2(Upper)	0x00
Value2(Lower)	0x01
Error Check CRC16(Lower)	0x18
Error Check CRC16(Upper)	0xC6

Response

Field	Data
Slave Address	0x01
Function Code	0x10
Start Address(Upper)	0x07
Start Address(Lower)	0xD0
Number of Registers(Upper)	0x00
Number of Registers(Lower)	0x02
Error Check CRC16(Lower)	0x41
Error Check CRC16(Upper)	0x45

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(4) Exception response

In case the query message is faulty, the Modbus Interface DIII will reply an exception response. In normal conditions the function code of the response message is the same as the query message. But in case of an error, 0x80 is added to the function code of the response message.

The exception response includes the exception code, indicating the cause of the error.

Exception code	Name	Cause
0x01	Illegal function	This function code is not supported.
0x02	Illegal data address	Access was attempted to an unassigned register
		address.
0x03	Illegal data	This query includes unauthorized data.

[Example of exception response]

In the case of setting an illegal mode to the holding register address 42002.

Query

Field	Data
Slave Address	0x01
Function Code	0x06
Start Address(Upper)	0x07
Start Address(Lower)	0xD1
Number of Registers(Upper)	0x01
Number of Registers(Lower)	0x0F
Error Check(Lower)	0x99
Error Check(Upper)	0x13

Response

Field	Data
Slave Address	0x01
Function Code	0x86
Exception Code	0x03
Error Check(Lower)	0x02
Error Check(Upper)	0x61

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2.2.2 Character format

Each byte of a message is sent as character data as follows.

A character consists of start bit (0), 8 bits data, parity bit and stop bit (1). One character size is always 11 bits and stop bit 1 or 2 is selected by parity bit.

[Non Parity]

0 (LSB)	1	2	3	4	5	6	7	8	9	10 (MSB)
Start bit				Data					Stop bit 1	Stop bit 2
[Parity]

0 (LSB)	1	2	3	4	5	6	7	8	9	10 (MSB)
Start bit				Data					Parity bit	Stop bit 2
									(Odd or
									Even)

2.2.3 Silent internal time

Every frame needs to have silent interval time (T1-T2-T3-T4) before and after. The silent interval time is depending on communication speed.

Baud Rate(bps)	9600	19200
Silent Interval Time(ms)	5	2,5
(T1-T2-T3-T4)

2.2.5 Response time

This Modbus Interface DIII responds a message after response time(t1) when this Modbus Interface DIII receives a query message. The response time(t1) of this adaptor is “Silent Interval Time(T1-T2-T3-T4) + 20ms”. Modbus master needs to wait to send next query message for time interval(t2) when the modbus master receives a response from the Modbus Interface DIII. The time interval(t2) should be more than “Silent Interval

Time(T1-T2-T3-T4) + 20ms”.

Modbus master	Query message				Query message

Modbus Interface DIII			Response
				t2

		t1
		t1
	t1 = (T1-T2-T3-T4) + 20 (ms)		t2 >= (T1-T2-T3-T4) + 20 (ms)

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2.3 Communication procedure

2.3.1 System initialisation

At startup:

- All input registers have values 0.

After the discovery of the DIII connected units, the “DIII unit connected status bit” (see Input registers 30002 till 30006) will be updated to “1: connected“ and the input registers of the connected DIII units (30001 and higher) will have the correct values.

- All the holding registers have initial values 0.

After the discovery of the DIII connected units, the “DIII unit connected status bit” (see input registers 30002 till 30006) will be updated to “1: connected” and the holding registers of the connected DIII units (42001 and higher) will be updated to the actual values once.

Attention: The holding values receive the actual values at the detection time only. This means this will only happen once. (Remark: also not during rediscovery)

Check status when Modbus Interface DIII is ready

BMS gets all DIII units connected addresses

BMS gets all DIII units capabilities

BMS gets all DIII units current status by reading the input registers and read all values of the holding registers

BMS		Modbus Interface DIII		DIII unit

Power on

Modbus Interface DIII status (30001 bit 0): Busy

Check Modbus Interface DIII status (30001)

Return: Busy

Retrieve status

Modbus Interface DIII status (30001 bit 0): Ready

Check Modbus Interface DIII status (30001)

Return: Ready

Check DIII unit connected status (30002-5)

Return: Ready

Check DIII unit capabilities

Return values

Check DIII unit status (input registers) & read holding registers

Return values

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2.3.2 Monitor and operate units from the BMS

Input registers of each DIII unit: 30001 and higher

The input registers will contain the status of the connected DIII units.

In case the DIII communication is interrupted (see Input registers 30006 till 30009): then the last communicated values will remain, until the DIII communication is restored.

Status changes are communicated continuously to the input registers, meaning the input registers will contain the actual values.

Holding registers of each DIII unit: 42001 and higher

- Writing instructions to change a unit status (Preset Single or Multiple Registers) When a value is written to a holding register, it will be communicated to the DIII units.

Attention: Modbus Interface DIII sends the command to a unit when the value of a Holding Register is changed. Especially in case that indoor units are operated from the user interface, the BMS should always get the status of indoor units and copy the received status to the Holding Registers.

Note: at start-up of the system (See 2.3.1 System initialisation) and the initial discovery of the DIII connected units, the Modbus Interface DIII put the actual status in the holding registers. (Remark: not during rediscovery.)

BMS checks communication status

Copy:

BMS gets all DIII units current status by reading the input registers and copies to the related bits (preset) to the holding registers

Command: BMS changes a value in the holding registers

BMS		Modbus Interface DIII		DIII unit

Check communication status (30006-9)

Return: status

Get DIII unit status (input registers)

Return values

Preset DIII unit status to the holding register

Preset On/Off bit to the holding register

Change on/off

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