---
title: Serial Input
slug: legacy-docs/serial-input
docTags: 
createdAt: 2025-03-11T06:56:07.599Z
---

:::hint{type="warning"}
This page / section pertains to **BrightAuthor Classic**, our legacy app. **BrightSign Author **is our latest app for managing content and players.

Development of BrightAuthor Classic has largely ceased and the app will eventually be deprecated and replaced with BrightSign Author.
:::

::Image[]{src="https://api.archbee.com/api/optimize/511c8QBH-VHiwWnyzIwUb/tusswyGvVfH78jErpdnGW_serial-input-icon.png" size="20" width="116" height="100" position="center" showCaption="false"}

The Serial Input event specifies the action that occurs when the BrightSign player receives input from a device connected to a serial port.

- **Specify port**: Enter the port number of the input device. Most standard RS-232 serial devices enumerate on port 0. If you are connecting a USB-serial device, it will enumerate on port 2. To configure the serial port, navigate to **[File > Presentation Properties > Interactive](docId\:dKUSdiVRXpUAiUOVm2eHL)**.
- **Specify serial input**: Enter the serial input string that will trigger the event. You can also use the \<\*> wildcard to match some or all of the serial input (i.e. entering "\<\*>" in this field will match any input, while entering "mycommand\_\<\*>" will match any input message that begins with "mycommand\_").

# Modify User Variables

You can use the Serial Input event to modify the values of User Variables. To enable these options, click the **Advanced** tab:

- **Assign input to variable?**: Check this box to assign the content of the serial input to a User Variable.
  - **Input specifies variable**: The serial input string will dynamically specify which User Variable to modify. The serial input string must be sent in the form of  \<variable name> : \<variable value>.
  - **Specify fixed variable**: The serial input string will modify a fixed User Variable. Use the dropdown list to choose which User Variable the serial input will modify. The serial input string must be sent in the form of \<variable value>.

:::hint{type="success"}
You can use the **Input specifies variable** option to modify more than one User Variable with a single event. Use the following serial input string:  \<variable name> : \<variable value> !! \<variable name> : \<variable value>
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- **Assign wildcard to variable?**: Check this box to specify the value of a User Variable using the \<\*> wildcard. Select the User Variable to modify using the dropdown menu to the right. The **Specify serial input** field must contain the \<\*> wildcard, either by itself or with additional text (e.g. "message\_\<\*>").

:::hint{type="warning"}
Wildcards are only supported when the serial port is using the ASCII [protocol](docId\:dKUSdiVRXpUAiUOVm2eHL), not when using the Binary protocol.
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:::hint{type="success"}
It is possible to check both **Assign input to variable** and **Input specifies variable** boxes for more complex functionality. For example, you can use **Specify fixed variable** to assign the entire serial input string to one variable, while at the same time using **Assign wildcard to variable** to assign a subset of that string to another variable.
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