---
title: "KNX Group Object DPT3"
canonical: "https://docs.cuesystem.com/space/CVCHELP/525336577/KNX%20Group%20Object%20DPT3"
format: markdown
---
> Macro (toc)

---

# Description

KNX Group Object DPT3 is amongst others used to realize relative dimming or moving blinds relative to a certain start position.

|  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Field |  |  |  |  | c | StepCode |

# DPT Dimensions

|  |  |  |  |
| --- | --- | --- | --- |
| DPT Dimensions | Name | c | StepCode |
| 3.007 | dimming control | 0 = Decrease brightness<br>1 = Increase brightness | The amount of intervals into which the range of 0% ÷ 100 % is subdivided or the break indication.<br>000b = Break<br>001b ÷ 111b = Step<br>Number of intervals = 2<sup>(newstepcode-1)</sup> |
| 3.008 | blind control | 0 = Move up<br>1 = Move down | The amount of intervals into which the range of 0% ÷ 100 % is subdivided, or the break indication.<br>000b = Break<br>001b ÷ 111b = Step<br>Number of intervals = 2<sup>(newstepcode-1)</sup> |

# WriteValue

This function transmits the KNX telegram including a command for dimming or moving blinds to the group address defined in the driver property. KNX native parameters are used in this function. This function returns True if the function success, else it returns False. A function GetLastError returns the error number that occurred while executing the command. The errors that can happen: <u>[10000](/wiki/spaces/CVCHELP/pages/510525445/Command+errors#10000)</u>, <u>[10002](/wiki/spaces/CVCHELP/pages/510525445/Command+errors#10002)</u>, <u>[10003](/wiki/spaces/CVCHELP/pages/510525445/Command+errors#10003)</u>, <u>[10004](/wiki/spaces/CVCHELP/pages/510525445/Command+errors#10004)</u>, <u>[10005](/wiki/spaces/CVCHELP/pages/510525445/Command+errors#10004)</u>.

#### Syntax

```visualbasic
Function WriteValue (
  c As Boolean,
  stepcode As Byte,
  Optional highpriority As Boolean := False) 
As Boolean
```

#### Parameters

c

Boolean It is the direction of dimming or moving blinds. If it is False, then decrease brightness or move up is applied. If it is True, then increasing the brightness or move down is applied.

stepcode

Byte It is the stepcode described in the table above. The allowed value is 0 to 7.

highpriority

Boolean Optional, defaults to False. If it is False, then the command is applied with standard priority on the KNX bus. If it is True, then the command is applied with a high priority on the KNX bus.

#### Return value

Boolean This function returns True on success or False if an error occurs. A function GetLastError returns the error number.

# WriteStep

This function transmits the KNX telegram including a command for dimming or moving blinds to the group address defined in the driver property. Programmer friendly parameter newstep is used in this function. This function returns True if the function success, else it returns False. A function GetLastError returns the error number that occurred while executing the command. The errors that can happen: 10000, 10002, 10003, 10004.

#### Syntax

```visualbasic
Function WriteStep (
  newstep As Double,
  Optional highpriority As Boolean := False) 
As Boolean
```

#### Parameters

newstep

Double It is the value of the required step in the range -100 ÷ 100. The nearest possible stepcode is evaluated in the command. When the value is out of range -100 ÷ 100, the maximum step is applied. A negative value means decreased brightness or moving up. A positive value means increased brightness or move down. Zero value is used for a break.

highpriority

Boolean Optional, defaults to False. If it is False, then the command is applied with standard priority on the KNX bus. If it is True, then the command is applied with a high priority on the KNX bus.

#### Return value

Boolean This function returns True on success or False if an error occurs. A function GetLastError returns the error number.

# GetValue

This function returns the last values of the group object with the given address received from the KNX bus.

#### Syntax

```visualbasic
Function GetValue(
  ByRef c As Boolean,
  ByRef stepcode As Byte)
```

#### Parameters

c

Boolean This ByRef parameter is set to the last received c value of the group object.

stepcode

Byte This ByRef parameter is set to the last received stepcode of the group object.

# GetStep

This function returns the last received value of the step in range -100 ÷ 100.

#### Syntax

```visualbasic
Function GetStep() As Double
```

#### Return value

Double It is the last received value of the step of the group object. Value is in the range -100 ÷ 100, zero means break.

# OnUpdate

This event is raised when the KNX telegram with the appropriate group address is received. It returns all possible formats of data received from the KNX telegram.

#### Syntax

```visualbasic
Event OnUpdate As Process (
  c As Boolean,
  stepcode As Byte,
  newstep As Double)
```

#### Parameters

c

Boolean It is the direction of dimming or moving blinds. If it is False, then decrease brightness or move up is applied. If it is True, then increase the brightness or move down is applied.

stepcode

Byte It is the stepcode described in the table above.

newstep

Double It is the value of the required step in the range -100 ÷ 100. A negative value means decrease brightness or move up. A positive value means increase brightness or move down. Zero value is used for a break.