# LED (and Display) Control series4x (Display) supports three modes for controlling its LEDs (and Display): - Automatic Scene Selection - Scene controlled by IO-Link-Process Data - Advanced Control by IO-Link Process Data The control mode can be selected via IO-Link parameter **LED Control Mode** (see [ISDU Indices](isdu-indices.md)). ## Automatic Scene Selection The LEDs (and Display) behave like the selected Scene. Scene n is selected by the state of Touch (Sensor actuation) and the state of the input pins E1 and E2:

LED Scene	Actuation Flag	E1	E2	None	Pin2 (E1)	Pin2 (E1) and Pin5 (E2)
0	0	0	0	✓	✓	✓
1	1	0	0	✓	✓	✓
2	0	1	0		✓	✓
3	1	1	0		✓	✓
4	0	0	1			✓
5	1	0	1			✓
6	0	1	1			✓
7	1	1	1			✓

The number of applicable scenes depends on parameter **Active Inputs**:

Active Inputs	Applicable Scenes
None (3 pin mode)	0, 1
Pin2 (E1) (4 pin mode)	0 ... 3
Pin2 (E1) and Pin5 (E2) (5 pin mode)	0 ... 7

## Scene Controlled by IO-Link Process Data The active Scene is set to the value written to the **LED Scene** field of the Process Data. For **LED Scene** = 255, the active Scene is selected by inputs like "Automatic Scene Selection" (LED Control Mode = 0). LEDs always act like described in the active Scene. The Display behavior depends on the **Display Mode** field of Process Data: It can show the Display Text of the selected Scene, or a number or a text given in the respective field of Process Data. ## Advanced Control by IO-Link Process Data The LED pattern, color, brightness, effect, and effect frequency is controlled by IO-Link process data. For more information see [Process Data](process-data.md). The LED indexing is clockwise starting from the top left LED (LED 1). ## Output Locking The "Output Locking" was designed for applications without IO-Link only. The sensor needs to be set to **LED Control Mode** "Automatic Scene selection". It locks the **Pin 4** output signal but has no impact on the **Actuation Flag**. The "Output Locking" has no influence on the scene or scene change. This means touching/inputs on E1/E2 will change the scene accordingly. For locking, the inputs must be set active (**Active Inputs** parameter). Output locking can be used to interrupt an infinite timer / terminate an output signal.