IntesisBox DK-RC-MBS-1, DK-AC-MBS-1 User Manual

IntesisBox

®

DK-RC-MBS-1 v.1.6

Modbus RTU (EIA-485) Interface for Daikin air conditioners.
Compatible with VRV and SKY line air conditioners commercialized
by Daikin.

User Manual

Issue Date: 12/2017

r3.3 EN

Order Codes:

DK-RC-MBS-1: Modbus RTU Interface for Daikin air conditioners

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

2/23

© Intesis Software S.L.U. 2017. All Rights Reserved.

Information in this document is subject to change without notice. No part of this publication
may be reproduced, stored in a retrieval system or transmitted in any form or any means
electronic or mechanical, including photocopying and recording for any purpose other than the
purchaser’s personal use without the written permission of Intesis Software S.L.U.

Intesis Software S.L.U.
Milà i Fontanals, 1 bis
08700 Igualada
Spain

TRADEMARKS
All trademarks and tradenames used in this document are acknowledged to be the copyright of
their respective holders.

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

3/23

INDEX

1. Presentation .......................................................................................................... 4

2. Connection ............................................................................................................ 5

2.1 Connect to the AC indoor unit ............................................................................... 5

2.2 Connection to the EIA-485 bus ............................................................................. 6

3. Quick Start Guide ................................................................................................... 6

4. Modbus Interface Specification ................................................................................ 7

4.1 Modbus physical layer.......................................................................................... 7

4.2 Modbus Registers ................................................................................................ 7

4.2.1 Control and status registers ........................................................................... 7

4.2.2 Configuration Registers.................................................................................. 9

4.2.3 Considerations on Temperature Registers ........................................................ 9

4.3 DIP-switch Configuration Interface ...................................................................... 11

4.4 Implemented Functions ..................................................................................... 15

4.5 Device LED indicator ......................................................................................... 15

4.6 EIA-485 bus. Termination resistors and Fail-Safe Biasing mechanism ...................... 16

5. Electrical and Mechanical features .......................................................................... 17

6. List of supported AC Unit Types. ............................................................................ 18

7. Error Codes ......................................................................................................... 19

8. Annex 1: Master/Slave of Operation Mode ............................................................... 23

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

4/23

1. Presentation

The DK-RC-MBS-1 interfaces allow a complete and natural
integration of Daikin air conditioners into Modbus RTU (EIA-

485) networks.

Compatible with all SKY Air and VRV models commercialized
by Daikin. Check the Section 6 to obtain more information.

Reduced dimensions. 93 x 53 x 58 mm

3.7” x 2.1” x 2.3”

• Quick and easy installation.

Mountable on DIN rail, wall, or even inside the indoor unit on some models of AC.

• External power not required.

• Direct connection to Modbus RTU (EIA-485) networks. Up to 63 DK-RC-MBS-1 devices can

be connected in the same network.

DK-RC-MBS-1 is a Modbus slave device.

• Direct connection to the AC indoor unit. Up to 16 AC indoor units can be connected to DK-

RC-MBS-1, controlling them as one (not individually).

• Configuration from both on-board DIP-switches and Modbus RTU.

• Total Control and Supervision.

• Real states of the AC unit's internal variables.

• Allows simultaneous use of the AC’s remote controls and Modbus RTU.

* Up to 63 IntesisBox devices can be installed in the same Modbus RTU bus. However, depending on the configured speed, the

installation of Modbus Repeaters may be required

• SCADA

• PLC

• DDC

• BMS

• HMI

• Controller

• etc

Up to 63
AC indoor
units*

Modbus RTU
EIA-485 network

Modbus RTU

Master

device

DK-RC-MBS-1

DK-RC-MBS-1
DK-RC-MBS-1

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

5/23

Connection to
P1P2 bus. Two
wire cable.

90 mm / 3.5”

53 mm / 2.1”

53 mm / 2.1”

90 mm

3.5”

2. Connection

The interface comes with a plug-in terminal block of 2 poles to establish direct connection with
the AC indoor unit. It comes as well with a plug-in terminal block of 2 poles to establish direct
connection with the Modbus RTU EIA-485 network.

2.1 Connect to the AC indoor unit

The DK-RC-MBS-1 connects directly to the Daikin P1P2 Bus, which is not provided within the
interface. Depending on which controllers are available, the recommended connection’ methods
are the following ones (details in Figure 2. 1):

• Wired remote control available. Connect the gateway as Slave in parallel with the

wired remote controllers (Controller acts as Master).

• Infrared remote control available. Connect the gateway as Master in parallel with the

infrared remote controller (Infrared Remote Control as Slave).

• No remote control available Connect the gateway directly to the P1P2 bus of the

indoor unit as Master when there is no Daikin Remote Controller.

Maximum P1 P2 bus length is 500 meters / 1,640.42 ft . The bus has no polarity sensitivity.

AC Indoor Unit

IntesisBox®

DK-RC-MBS-1

MODBUS

RTU

EIA-485

Bus

EIA485

A+ B-

P1 P2

For wall mounting
extract the upper
and lower staples
until you hear the
"click".

P1 P2

DAIKIN

Internal
electronic
control

Remote Controller

P2
P1

IntesisBox®

DK-RC-MBS-1

MODBUS

RTU

EIA-485

Bus

EIA485

A+ B-

P1 P2

AC Indoor Unit

Internal
electronic
control

Connection to P1P2
bus. Two wire cable.

P2
P1

Max. 500m / 1,640.42 ft

Max. 500m / 1,640.42 ft

Figure 2. 1 DK-RC-MBS-1 Connection diagrams

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

6/23

2.2 Connection to the EIA-485 bus

Connect the EIA-485 bus wires to the plug-in terminal block (the one of two poles) of DK-RC­MBS-1 and keep the polarity on this connection (A+ and B-). Make sure that the maximum
distance to the bus is 1,200 meters (3,937 ft). Loop or star typologies are not allowed in the
case of the EIA-485 bus. A terminator resistor of 120Ω must be present at each end of the bus
to avoid signal reflections. The bus needs a fail-safe biasing mechanism (see section 4.6 for
more details).

3. Quick Start Guide

1. Disconnect the air conditioning from the Mains Power.

2. Attach the interface next to the AC indoor unit (wall mounting) following the instructions

of the diagram below or install it inside the AC indoor unit (respect the safety
instructions given).

3. Connect the P1P2 bus between the interface and the AC indoor unit following the

instructions of the diagram. Screw each bare cable end in the corresponding P1P2
terminals of each device.

4. Connect the EIA-485 bus to the connector EIA485 of the interface.

5. Close the AC indoor unit.

6. Check the DIP-Switch configuration of the IntesisBox interface and make sure it matches

the current installation’s parameters (see section 4.3).

By default, the interface is set to:

▪ Modbus Slave Address  1
▪ Modbus baud rate  9600 bps

These parameters can be modified from SW4 and SW3 DIP-Switches.

All other switch positions are set at low level (Off position ) by default.

NOTE: All changes on the DIP-Switch configuration require a system power cycle to be
applied.

7. Connect the AC system to Mains Power.

IMPORTANT: The IntesisBox interface requires to be connected to the AC unit
(powered) to start communicating.

ON

ON

SW3

SW4

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

7/23

4. Modbus Interface Specification

4.1 Modbus physical layer

DK-RC-MBS-1 implements a Modbus RTU (Slave) interface, to be connected to an EIA-485 line.
It performs 8N2 communication (8 data bits, no parity and 2 stop bit) with several available
baud rates (2400 bps, 4800 bps, 9600 bps -default-, 19200 bps, 38400 bps, 57600 bps, 76800
bps and 115200 bps). It also supports 8N1 communication (8 data bits, no parity and 1 stop
bit).

4.2 Modbus Registers

All registers are type “16-bit unsigned Holding Register” and they use the standard Modbus big
endian notation.

4.2.1 Control and status registers

Register Address

(protocol address)

Register Address

(PLC address)

R/W

Description

0

1

R/W

AC unit On/Off

▪ 0: Off
▪ 1: On

1

2

R/W

AC unit Mode 1

▪ 0: Auto
▪ 1: Heat
▪ 2: Dry
▪ 3: Fan
▪ 4: Cool

2

3

R/W

AC unit Fan Speed 1

▪ 1: Low
▪ 2: Mid
▪ 3: High

3

4

R/W

AC unit Vane Position 1

▪ 1: Position-1 (Horizontal)
▪ 2: Position-2 (Horizontal)
▪ 3: Position-3 (Medium)
▪ 4: Position-4 (Vertical)
▪ 5: Position-5 (Vertical)
▪ 10: Swing

4

5

R/W

AC unit Temperature Setpoint

1,2,3

▪ -32768 (Initialization value)
▪ 16..31ºC (ºC/x10ºC)
▪ 61..92ºF

5

6

R

AC unit Temperature reference

1,2,3

▪ -32768 (Initialization value)
▪ 10..38ºC (ºC/x10ºC)
▪ 50..100ºF

1

Available values will depend on the AC unit mode. Check the AC unit model functions in its user manual to know the possible v alues for

this register.

2

Magnitude for this register can be adjusted to Celsius x 1ºC, Celsius x 10ºC (default) or Fahrenheit. See section 4.2.3 for more

information.

3

It is not possible turn to x10 the value shown in Fahrenheit.

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

8/23

Register Address

(protocol address)

Register Address

(PLC address)

R/W

Description

6

7

R/W

Window Contact

▪ 0: Closed (Default)
▪ 1: Open

7

8

R/W

DK-RC-MBS-1 Disablement 4

▪ 0: DK-RC-MBS-1 enabled (Default value)
▪ 1: DK-RC-MBS-1 disabled

8

9

R/W

AC Remote Control Disablement 4

▪ 0: Remote Control enabled (Default value)
▪ 1: Remote Control disabled

9

10

R/W

AC unit Operation Time 4

▪ 0..65535 (hours). Counts the time the AC

unit is in “On” state.

10

11

R

AC unit Alarm Status

▪ 0: No alarm condition
▪ 1: Alarm condition

11

12

R

Error Code 5

▪ 0: No error present
▪ 65535(-1 if it is read as signed value): Error

in the communication of DK-RC-MBS-1 with
the AC unit.

▪ Any other error present, see the table at the

end of this document.

22

23

R/W

Indoor unit´s ambient temperature from
external sensor (at Modbus side)

1,2,3,6,7

▪ -32768: (Initialization value). No

temperature is being provided from an
external sensor.

▪ Any other: (ºC/x10ºC/ºF)

23

24

R

AC Real temperature setpoint

1,2,3,6

▪ When no external temperature is provided,

this read-only register will have the same
value as register 5 (PLC addressing). In all
cases, it will show the current setpoint in the
indoor unit.

▪ 16..31ºC (ºC/x10ºC)
▪ 60..90ºF

26

27

R/W

AC unit Horizontal Vane Position 1

▪ 0: Auto (Default Value)
▪ 10: Swing

55

56

R/W

Under voltage counter 1

▪ 0..300

97

98

R/W

Block Periodic Sendings

4,8,9

▪ 0: Non-blocked (Default value)
▪ 1: Blocked

4

This value is stored in non-volatile memory

5

See section 7 for possible error codes and their explanation

6

See section 4.2.3 for more information

7

This register is available in firmware version 0.8 onwards

8

If the register is configured as “0: Non-blocked”, all commands received from Modbus will be sent to the AC system. If “1: Blocked”,

commands from Modbus will only be sent to the AC system if they differ from the previous value.

9

This register applies to firmware version 1.6 onwards

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

9/23

4.2.2 Configuration Registers

Register Address

(protocol address)

Register Address

(PLC address)

R/W

Description

13

14

R/W

“Open Window” switch-off timeout 10

▪ 0..30 (minutes)
▪ Factory setting: 30 (minutes)

14

15

R

Modbus RTU baud-rate

▪ 2400bps
▪ 4800bps
▪ 9600bps (Default)
▪ 19200bps
▪ 38400bps
▪ 57600bps
▪ 76800bps
▪ 115200bps

15

16

R

Modbus Slave Address

▪ 1..63

21

22

R

Max number of fan speeds

48

49

R

Switch value

49

50

R

Device ID: 0x0801

50

51

R

Software version

4.2.3 Considerations on Temperature Registers

• AC unit temperature setpoint (R/W)

(register 4 – in Protocol address / register 5 – in PLC address):
This is the adjustable temperature setpoint value that must be required by the user. This
register can be read (Modbus function 3 or 4) or written (Modbus functions 6 or 16). A
remote controller connected to the Daikin indoor unit will report the same temperature
setpoint value as this register, but only will happen when no AC unit´s external
reference is provided from DK-RC-MBS-1 (see detail for register 22/23 below).

• AC unit temperature reference (R)

(register 5 – in Protocol address / register 6 – in PLC address):
This register reports the temperature that is currently used by the Daikin indoor unit as
the reference of its own control loop. Depending on the configuration of the indoor unit,
this value can be the temperature reported by the sensor on the return path of the
Daikin indoor unit or the sensor of its remote controller. It is a read-only register
(Modbus functions 3 or 4).

• AC unit external temperature reference (Modbus) (R/W)

(register 22 – in Protocol address / register 23 – in PLC address):
This register allows us to provide an external temperature’s sensor from the Modbus
side. Daikin indoor unit does not allow on devices like DK-RC-MBS-1 to provide directly
temperature to be used as a reference of the control loop of the AC indoor unit. In order
to overcome this limitation and enable the usage of an external temperature sensor
(i.e.from Modbus side), DK-RC-MBS-1 applies the following mechanism (only if “external
temperature’s reference” is being used):

10

Once window contact is open, a count-down to switch off the AC Unit will start from this configured value.

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

10/23

o After a couple of values have been entered in the “AC unit external temperature’s

reference” (register 22/23) and “AC unit temperature set point” (register 4/5),
DK-RC-MBS-1 is going to estimate the temperature chosen implied (e.g. if a
“temperature setpoint (register 4/5)” of 22ºC, and an “external temperature
reference (register 22/23)” of 20ºC are entered, DK-RC-MBS-1 will assume that
the user is demanding a +2ºC increase in temperature).

o By knowing at any time the ambient temperature currently used by the indoor

unit to control its own operation (register 5/6), DK-RC-MBS-1 can calculate the
required temperature setpoint needed to apply the decrease/increase on the real
temperature and reach the temperature chosen by the user (following the
example above, if DK-RC-MBS-1 reads an “ambient temperature” (register 5/6)
of 24ºC in the indoor unit, it will apply a final setpoint of 24ºC + 2ºC = 26ºC).

o At this moment, each time that DK-RC-MBS-1 detects a change on the ambient

temperature reported by the indoor unit (register 5/6), it will also change the
required setpoint, in order to keep the temperature required by the user at any
time. If we follow the last example, if DK-RC-MBS-1 receives a new
temperature´s value coming from the indoor unit of 25ºC, DK-RC-MBS-1 will
automatically adjust the temperature setpoint required of the AC indoor unit to
25ºC + 2ºC = 27ºC).

o In general, DK-RC-MBS-1 is constantly applying the “Virtual Temperature”

formula:

SAC = Su – ( Tu – T

AC

)

Where:

SAC - setpoint value currently applied to the indoor unit
Su - setpoint value written at Modbus side (register 4/5)
Tu - external temperature reference written at Modbus side (register 22/23)
TAC - ambient temperature that the indoor unit is using as the reference of its

own control loop (register 5/6)

When DK-RC-MBS-1 detects a change in any of the values of

{ Su , Tu , TAC }, it will send the new setpoint (SAC) to the indoor unit.

o After the startup, the value for “external temperature’s reference” (register

22/23) has a value -32768 (0x8000). This value means that no external
temperature reference is being provided through DK-RC-MBS-1. In this scenario,
the setpoint value shown in register 4/5 is always the same as the current
setpoint value of the indoor unit. The AC indoor unit will use its own return path
temperature sensor as reference for its control loop.

o When the mechanism of “Virtual Temperature” is applied. The temperature

setpoint’s value shown by the Remote Controller or other Control System from

Daikin connected to the indoor unit may show a different value from the value
shown in register 4/5.

o If it is desired to use the temperature’s reading from the Remote Control as the

external temperature reference (Tu ,register 22/33), the Remote Controller must
be configured as Master, and the Daikin AC indoor unit must have the option
“thermostat sensor in the Remote Controller” as activated. This configuration is
done via a Daikin Remote Controller connected to the indoor unit and must be
done by Daikin authorized installers while the AC is being installed.

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

11/23

o When DK-RC-MBS-1 is set as “Master” of P1P2 bus, the external temperature’s

sensor connected to Modbus RTU EIA-485 network provides directly the value
currently applied to the indoor unit ( SAC ), and the process of the Virtual
temperature is not applied. In this case, the Remote Controller or any other
Control System connected from Daikin is not able to send the external
temperature reference’s value to the register 22/23.

• AC Real temperature setpoint (R)

(register 23 – In Protocol address / register 24 – in PLC address):
As it has been detailed on the previous point, the real temperature setpoint in the indoor

unit and the temperature setpoint requested from DK-RC-MBS-1 might differ (when a
value in register 22/23 – “external temperature reference” is entered). This register
always informs about the current temperature setpoint which is being used by the indoor
unit – it is also includes the temperature setpoint that will be shown by an additional
remote controller from Daikin connected to the indoor unit, if it is present on the system.

Moreover, notice that temperature’s values of all these four registers are expressed according to
the temperature´s format configured through its onboard DIP-Switches (See “4.3 - DIP-switch
Configuration Interface”). These following formats are possible:

• Celsius value: Value in Modbus register is the temperature value in Celsius (i.e. a

value “22” in the Modbus register must be interpreted as 22ºC)

• Decicelsius value: Value in Modbus register is the temperature value in

decicelsius (i.e. a value “220” in the Modbus register must be interpreted as

22.0ºC)

• Fahrenheit value: Value in Modbus register is the temperature value in

Fahrenheit (i.e. a value “72” in the Modbus register must be interpreted as 72ºF

(~22ºC).

4.3 DIP-switch Configuration Interface

All the configuration values on DK-RC-MBS-1 can be written and read from Modbus interface.
Otherwise, some of them can also be setup from its on-board DIP-switch interface.
The device has DIP-switches SW1, SW3 and SW4 on the following locations:

SW3

SW4

IntesisBox®

DK-RC-MBS-1

EIA485

A+ B-

P1 P2

AC Unit

SW1

SW1

SW4

ON

1 2 3 4

ON

SW3

1 2 3 4

1 2 3 4 5 6 7 8

ON

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

12/23

The following tables apply to the interface´s configuration through DIP-switches:

SW1 – AC indoor unit’s features

SW1-P1..4

Description

Slave - A Daikin BRC Controller must be present in P1P2 bus, configured as Master (Default value)

Master – Daikin BRC Controller not needed in P1P2 bus. If it exists, it must be configured as Slave

Master of Operation Mode (For VRV only) (Default value) 11

Slave of Operation Mode (For VRV only)

Reserved, not used (Default value)

Reserved, not used

Daikin Indoor Unit ambient temperature reading (Default value) 12

Daikin Remote Controller ambient temperature reading

Table 4.1 SW1: AC indoor unit´s features

SW3/SW4 – Baud rate configuration

SW3-P7..8

SW4-P3

Description

2400bps

4800bps

9600bps (Default value)

19200bps

38400bps

57600bps

76800bps

115200bps

Table 4.2 SW3-SW4: Modbus baud rate

11

Explanation in Section 8 of this document

12

From firmware version 1.2 onwards

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

13/23

SW4 – Degrees/Decidegrees (x10), temperature magnitude (ºC/ºF) and EIA-485 termination
resistor.

Table 4.3 SW4: Temperature and termination resistor configuration

SW4-P1..2-4

Description

Temperature values in Modbus register are represented in degrees (x1) (Default value)

Temperature values in Modbus register are represented in decidegrees (x10)

Temperature values in Modbus register are represented in Celsius degrees (Default value)

Temperature values in Modbus register are represented in Fahrenheit degrees

EIA-485 bus without termination resistor (Default value)

Internal termination resistor of 120Ω connected to EIA-485 bus

ON

ON

ON

ON

ON

ON

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

14/23

SW3 – Modbus Slave address

Table 4.4 SW3: Modbus slave address

Add SW3-P1..6

Add SW3-P1..6

Add SW3-P1..6

Add SW3-P1..6

Add SW3-P1..6

0

13

26

39

52

1

14

27

40

53

2

15

28

41

54

3

16

29

42

55

4

17

30

43

56

5

18

31

44

57

6

19

32
45

58

7

20

33
46

59

8

21

34

47

60

9

22

35

48

61

10

23

36
49

62

11 24 37 50 63

12 25 38 51

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

ON

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

15/23

4.4 Implemented Functions

DK-RC-MBS-1 implements the following standard Modbus functions:

▪ 3: Read Holding Registers
▪ 4: Read Input Registers
▪ 6: Write Single Register
▪ 16: Write Multiple Registers (Despite this function is allowed, the interface does not

allow to write operations on more than 1 register with the same request, this means that
length field should be always be 1 when this function is being used in case of writing)

4.5 Device LED indicator

The device includes two LED indicators to show all the possible operational states. In the
following table there are written the indicators which can be performed and their meaning.

L1 (green LED)

Device status

LED indication

ON / OFF Period

Description

During not normal
operation

LED blinking

500ms ON / 500ms OFF

Communication error

During normal
operation

LED flashing

100ms ON / 1900ms OFF

Normal operation (configured and
working properly)

L2 (red LED)

Device status

LED indication

ON / OFF Period

Description

During not normal
operation

LED Pulse

3sec ON / --- OFF

Under voltage

L1 (green LED) & L2 (red LED)

Device status

LED indication

ON / OFF Period

Description

During normal
operation

LED Pulse

5sec ON / --- OFF

Device Start-up

During not normal
operation

LED alternatively

blinking

500ms ON / 500ms OFF

Flash checksum not OK

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

16/23

4.6 EIA-485 bus. Termination resistors and Fail-Safe Biasing

mechanism

EIA-485 bus requires a 120Ω terminator resistor at each end of the bus to avoid signal
reflections.

In order to prevent fail status detected by the receivers, which are “listening” the bus, when all
the transmitters’ outputs are in three-state (high impedance), it is also required a fail-safe
biasing mechanism. This mechanism provides a safe status (a correct voltage level) in the bus
when all the transmitters’ outputs are in three-state. This mechanism must be supplied by the
Modbus Master.

The DK-RC-MBS-1 device includes an on-board terminator resistor of 120Ω that can be
connected to the EIA-485 bus by using DIP-switch SW4.

Some Modbus RTU EIA-485 Master devices can provide also internal 120Ω terminator resistor
and/or fail-safe biasing mechanism (check the technical documentation of the Master device
connected to the EIA-485 network in each case).

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

17/23

5. Electrical and Mechanical features

Enclosure

Plastic, type PC (UL 94 V-0)
Net dimensions (dxwxh):
93 x 53 x 58 mm / 3.7” x 2.1” x 2.3”
Color: Light Grey. RAL 7035

Operation
Temperature

0ºC to +60ºC

Weight

85 g.

Stock
Temperature

-20ºC to +85ºC

Mounting

Wall
DIN rail EN60715 TH35.

Operational
Humidity

<95% RH, non-condensing

Terminal Wiring
(for low-voltage
signals)

For terminal: solid wires or stranded wires
(twisted or with ferrule)

1 core: 0.5mm2… 2.5mm2
2 cores: 0.5mm2… 1.5mm2

3 cores: not permitted

Stock Humidity

<95% RH, non-condensing

Modbus RTU
port

1 x Serial EIA485 Plug-in screw terminal
block (2 poles):

A, B
Compatible with Modbus RTU EIA-485
networks

Isolation voltage

1500 VDC

AC unit port

1 x P1P2 bus Plug-in screw terminal block
(2 poles):

P1, P2
Compatible with Daikin networks

Isolation
resistance

1000 MΩ

Switch 1
(SW1)

1 x DIP-Switch for AC features

Protection

IP20 (IEC60529)

Switch 3
(SW3)

1 x DIP-Switch for Modbus RTU settings

LED indicators

2 x Onboard LED - Operational
status

Switch 4
(SW4)

1 x DIP-Switch for extra functions

EIA-485

Port

AC Unit

connection

DIP

Switch SW3

DIP

Switch SW1

LED

Indicators

DIP

Switch SW4

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

18/23

6. List of supported AC Unit Types.

A list of Daikin indoor unit model’s references compatible with DK-RC-MBS-1 and its available
features can be found on this link:

https://www.intesisbox.com/intesis/support/compatibilities/IntesisBox_DK-RC-xxx-1_AC_Compatibility.pdf

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

19/23

7. Error Codes

Error Code

Modbus

Error in
Remote

Controller

Error

category

Error Description

0

N/A

DK-RC-MBS-1

No active error

17

A0

External protection devices activated

18

A1

Indoor unit PCB assembly failure

19

A2

Interlock error for fan

20

A3

Drain level system error

21

A4

Temperature of heat exchanger (1) error

22

A5

Temperature of heat exchanger (2) error

23

A6

Fan motor locked, overload, over current

24

A7

Swing flap motor error

25

A8

Overcurrent of AC input

26

A9

Electronic expansion valve drive error

27

AA

Heater overheat

28

AH

Dust collector error / No-maintenance filter error

30

AJ

Indoor

Capacity setting error (indoor)

31

AE

Unit

Shortage of water supply

32

AF

Malfunctions of a humidifier system (water leaking)

33

C0

Malfunctions in a sensor system

36

C3

Sensor system of drain water error

37

C4

Heat exchanger (1) (Liquid pipe) thermistor system
error

38

C5

Heat exchanger (1) (Gas pipe) thermistor system error

39

C6

Sensor system error of fan motor locked, overload

40

C7

Sensor system of swing flag motor error

41

C8

Sensor system of over-current of AC input

42

C9

Suction air thermistor error

43

CA

Discharge air thermistor system error

44

CH

Contamination sensor error

45

CC

Humidity sensor error

46

CJ

Remote control thermistor error

47

CE

Radiation sensor error

48

CF

High pressure switch sensor

49

E0

Protection devices activated

50

E1

Outdoor unit PCB assembly failure

52

E3

High pressure switch (HPS) activated

53

E4

Low pressure switch (LPS) activated

54

E5

Overload of inverter compressor motor

55

E6

Over current of STD compressor motor

56

E7

Overload of fan motor / Over current of fan motor

57

E8

Over current of AC input

58

E9

Electronic expansion valve drive error

59

EA

Four-way valve error

60

EH

Pump motor over current

61

EC

Outdoor

Water temperature abnormal

62

EJ

Unit

(Site installed) Protection device activated

63

EE

Malfunctions in a drain water

64

EF

Ice thermal storage unit error

65

H0

Malfunctions in a sensor system

66

H1

Air temperature thermistor error

67

H2

Sensor system of power supply error

68

H3

High Pressure switch is faulty

69

H4

Low pressure switch is faulty

70

H5

Compressor motor overload sensor is abnormal

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

20/23

71

H6

Compressor motor over current sensor is abnormal

72

H7

Overload or over current sensor of fan motor is
abnormal

73

H8

Sensor system of over-current of AC input

74

H9

Outdoor air thermistor system error

75

HA

Discharge air thermistor system error

76

HH

Pump motor sensor system of over current is abnormal

77

HC

Water temperature sensor system error

79

HE

Sensor system of drain water is abnormal

80

HF

Ice thermal storage unit error (alarm)

81

F0

No.1 and No.2 common protection device operates.

82

F1

No.1 protection device operates.

83

F2

No.2 protection device operates

84

F3

Discharge pipe temperature is abnormal

87

F6

Temperature of heat exchanger(1) abnormal

91

FA

Discharge pressure abnormal

92

FH

Oil temperature is abnormally high

93

FC

Suction pressure abnormal

95

FE

Oil pressure abnormal

96

FF

Oil level abnormal

97

J0

Sensor system error of refrigerant temperature

98

J1

Pressure sensor error

99

J2

Current sensor error

100

J3

Discharge pipe thermistor system error

101

J4

Low pressure equivalent saturated temperature sensor
system error

102

J5

Outdoor

Suction pipe thermistor system error

103

J6

Unit

Heat exchanger(1) thermistor system error

104

J7

Heat exchanger(2) thermistor system error

105

J8

Oil equalizer pipe or liquid pipe thermistor system error

106

J9

Double tube heat exchanger outlet or gas pipe
thermistor system error

107

JA

Discharge pipe pressure sensor error

108

JH

Oil temperature sensor error

109

JC

Suction pipe pressure sensor error

111

JE

Oil pressure sensor error

112

JF

Oil level sensor error

113

L0

Inverter system error

116

L3

Temperature rise in a switch box

117

L4

Radiation fin (power transistor) temperature is too high

118

L5

Compressor motor grounded or short circuit, inverter
PCB fault

119

L6

Compressor motor grounded or short circuit

120

L7

Over current of all inputs

121

L8

Compressor over current, compressor motor wire cut

122

L9

Stall prevention error (start-up error) Compressor
locked, etc.

123

LA

Power transistor error

125

LC

Communication error between inverter and outdoor
control unit

129

P0

Shortage of refrigerant (thermal storage unit)

130

P1

Power voltage imbalance, open phase

132

P3

Sensor error of temperature rise in a switch box

133

P4

Radiation fin temperature sensor error

134

P5

DC current sensor system error

135

P6

AC or DC output current sensor system error

136

P7

Total input current sensor error

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

21/23

142

PJ

Capacity setting error (outdoor)

145

U0

Low pressure drop due to insufficient refrigerant or
electronic expansion valve error, etc.

146

U1

Reverse phase, Open phase

147

U2

Power voltage failure / Instantaneous power failure

148

U3

System

Failure to carry out check operation, transmission error

149

U4

Communication error between indoor unit and outdoor
unit, communication error between outdoor unit and BS
unit

150

U5

Communication error between remote control and
indoor unit / Remote control board failure or setting
error for remote control

151

U6

Communication error between indoor units

152

U7

Communication error between outdoor units /
Communication error between outdoor unit and ice
thermal storage unit

153

U8

Communication error between main and sub remote
controllers (sub remote control error) / Combination
error of other indoor unit / remote control in the same
system (model)

154

U9

Communication error between other indoor unit and
outdoor unit in the same system / Communication error
between other BS unit and indoor/outdoor unit

155

UA

System

Combination error of indoor/BS/outdoor unit (model,
quantity, etc.), setting error of spare parts PCB when
replaced

156

UH

Improper connection of transmission wiring between
outdoor and outdoor unit outside control adaptor

157

UC

Centralized address duplicated

158

UJ

Attached equipment transmission error

159

UE

Communication error between indoor unit and
centralized control device

160

UF

Failure to carry out check operation Indoor-outdoor,
outdoor-outdoor communication error, etc.

209

60

All system error

210

61

PC board error

211

62

Ozone density abnormal

212

63

Contamination sensor error

213

64

Indoor air thermistor system error

214

65

Outdoor air thermistor system error

217

68

HVU error (Venti-air dust-collecting unit)

219

6A

Dumper system error

220

6H

Door switch error

221

6C

Replace the humidity element

222

6J

Replace the high efficiency filter

223

6E

Replace the deodorization catalyst

224

6F

Simplified remote controller error

226

51

Fan motor of supply air over current or overload

227

52

Fan motor of return air over current / Fan motor of
return air overload

228

53

Others

Inverter system error (supply air side)

229

54

Inverter system error (return air side)

241

40

Humidifying valve error

242

41

Chilled water valve error

243

42

Hot water valve error

244

43

Heat exchanger of chilled water error

245

44

Heat exchanger of hot water error

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

22/23

258

31

The humidity sensor of return air sensor

259

32

Outdoor air humidity sensor error

260

33

Supply air temperature sensor error

261

34

Return air temperature sensor error

262

35

Outdoor air temperature sensor error

263

36

Remote controller temperature sensor error

267

3A

Water leakage sensor 1 error

268

3H

Water leakage sensor 2 error

269

3C

Dew condensation error

339

M2

Centralized remote controller PCB error

345

M8

Communication error between centralized remote
control devices

347

MA

Centralized remote control devices inappropriate
combination

349

MC

Centralized remote controller address setting error

65535

(-1)

N/A

DK-RC-MBS-1

Error in the communication of DK-RC-MBS-1 with the
AC unit

In case to detect an error code not listed, contact your closest Daikin technical support service.

DK-RC-MBS-1

User’s Manual r3.3 EN

© Intesis Software S.L.U. - All rights reserved

This information is subject to change without notice

IntesisBox® is a registered trademark of Intesis Software SLU

URL
Email
Phone

http://www.intesisbox.com
[e-mail]
[phone]

23/23

8. Annex 1: Master/Slave of Operation Mode

The Master/Slave of Operation mode only applies under the following conditions:

1. The AC system is VRV

2. The VRV system uses a Heat pump as outdoor unit

3. There more than one indoor unit in a unique system working at different modes

(Table 8.1)

If they are not matched the parameter is going to be ignored.

The Heat pump outdoor unit of a VRV system can only work in one mode (either Heat, Cool or
fan). The Master of mode is the indoor unit that defines which is the working mode of the
outdoor unit. If no unit has been chosen as the one that defines the working mode of outdoor
unit, the first indoor unit to be turned On is the one which is going to define and control the
mode.

In a VRV system, there is only one device acting as Master of Mode. If more than one is
configured in this way, the system is not going to work properly. The configuration will be
determined by the Remote Controller of Daikin. The unit which controls the Operation mode
must have installed a Remote Controller.

When a DK-RC-MBS-1 is configured as Master of Mode via the Remote Controller of its indoor
unit, it can control all the modes of the system. The Mode selection of the gateways remaining
and remote controllers installed in the indoor units remaining is going to be affected by the one
chosen as Master of Mode. These ones are going to acquire the Slave of mode configuration, not
being able to change to any mode selection out of the Table 8.1.

Master of Mode

Mode of operation (as Slave of mode of Operation)

Heat

Heat, Fan

Dry

Cool, Fan, Dry

Fan

Fan

Cool

Cool, Fan, Dry

Table 8.1 Master and Slave of Mode configuration