---
title: "LED Switching and flashing"
slug: "led-switching-and-flashing"
updated: 2024-07-04T11:11:04Z
published: 2024-07-04T11:11:04Z
canonical: "docs-linescan.alliedvision.com/led-switching-and-flashing"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs-linescan.alliedvision.com/llms.txt
> Use this file to discover all available pages before exploring further.

# LED Switching and flashing

You can switch on and off or flash the Corona II modules. Switching on and off the Corona II module is suitable when the scanned object appears in front of the camera. Flashing is suitable for line synchronization.

- Connect the plug of the LED module to port X6 of the XLC4 control unit. Pin 1 Signal and Pin 6 Ground

> [!NOTE]
> Note
> 
> Do not use the shutdown port X2 for this application. X2 is intended for use with safety switches.

## Timing and limitations

### XLC4-1 (CP000411)

| Parameter | Notes | Min | Nominal | Max | Unit |
| --- | --- | --- | --- | --- | --- |
| Flash frequency | T1 | 1 | 10 | 20 | kHz |
| Trigger pulse | T2 | 10 | 20 |  | µs |
| ON-Delay D1 | for input voltage 4.5 V |  | 10 |  | µs |
| for input voltage 10 V |  | 3 |  | µs |
| OFF-Delay D2 | for input voltage 4.5 V |  | 20 |  | µs |
| for input voltage 10 V |  | 60 |  | µs |

### XLC4-1A (CP000411-1A) and XLC4-1F4 (CP000411-1F4)

| Parameter | Notes | Min | Nominal | Max | Unit |
| --- | --- | --- | --- | --- | --- |
| Flash frequency | T1/Tp | 200 |  | 60 | kHz |
| Light pulse | T2/Ton | 10 |  |  | µs |
| ON-OFF Delay | D1, D2 |  | < 1 |  | µs |
| Rise time | tr |  | < 0.5 |  | µs |
| OFF-time | Toff | 2 |  | 5000 | µs |

![](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/image(28).png)![](https://cdn.document360.io/eca58697-9c2f-461e-9f0a-e6205b74b693/Images/Documentation/image(29).png)Signal diagrams flash operation

For XLC4-1 and XLC4-1A the ON signal is applied to all four channels.

For XLC4-1F4 the ON signal can be applied for all four channels synchronously or for euch channel independently.

## Setting up the flashing

1. Activate Command mode using [command MO](/v1/docs/command-mo).
2. Use [command FA](/v1/docs/command-fa) to set the flash mode.

> [!NOTE]
> NOTE
> 
> Use higher currents (> 500 mA) at very low pulse durations to allow the capacitors charge between the pulses for constant light output.