TV Serial Commands

Owned by BrightSign TechDocs
Last updated: Feb 23, 2024
3 min read

This page outlines how to use serial I/O to issue commands to a TV display through a BrightSign player. Once a player and TV have been connected by RS-232 through DB9, USB, or 3.5mm serial cables, presentations can deliver commands as scheduled through BrightAuthor. Proper use of this document requires knowledge of BrightSign player serial port configuration.

Connecting Devices

RS-232 communication is conducted between two interface types: Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE). In order to connect a BrightSign player and TV for serial I/O, the interface types on the two devices must be determined. Most BrightSign players function as a DCE devices, while TVs may vary. Consult documentation for both the player and TV to determine if they are DTE or DCE.

Straight-through cabling only supports DTE to DCE connections. If both devices are DTE or DCE, a connection can be established through a null-modem cable or transformer, which flips RX/TX signals. 

Issuing Commands

The DE-9 (more commonly referred to as DB-9) serial port is fully RS-232 compatible, but the 3.5mm serial port can only interoperate with some RS-232 compatible devices. It can receive from any RS-232 device, but transmission may not work depending on the electrical characteristics of the devices.

After the connection between devices is established, commands can be sent from the player to the TV. Commands can typically be found in the TV manufacturer documentation. BrightAuthor can only send decimal or ASCII values; however, many TVs operate in other numeric systems like hexadecimal. Be sure to properly convert the command value to decimal or ASCII before entering the serial bytes. BrightSign players can support sending commands in hexadecimal and binary through the use of third party scripts and plugins. For more information on how to do this, contact our support.

The following is an example of how to send a command in decimal:

  1. Create an Interactive presentation in BrightAuthor.

  2. Open the media state or event where you want to send the command.

  3. Click the Advanced tab.

  4. Click Add Command and set the command to Send – Serial Bytes.

  5. Set the Port to 0 (standard case for most serial devices). Note that a USB-serial device (such as a GPS receiver) will enumerate on port 2. Additional USB-serial devices will enumerate on ports 3, 4, 5, etc. The enumeration order will remain consistent between reboots as long as the USB-serial devices are connected to the same player/hub ports. The enumeration order can be retrieved using the "usblist" command at the brightsign> shell prompt; otherwise, it will need to be determined by testing the setup.

  6. Enter the command in the Bytes field. Use a comma to separate each byte.

The following is an example of how to send a command in ASCII:

  1. Create an Interactive presentation in BrightAuthor.

  2. Open the media state or event where you want to send the command.

  3. Click on the Advanced tab.

  4. Click Add Command and set the command to Send – Serial String (EOL).

  5. Set the Port to 0 (standard case for most serial devices). Note that a USB-serial device (such as a GPS receiver) will enumerate on port 2. Additional USB-serial devices will enumerate on ports 3, 4, 5, etc. The enumeration order will remain consistent between reboots as long as the USB-serial devices are connected to the same player/hub ports. The enumeration order can be retrieved using the "usblist" command at the brightsign> shell prompt; otherwise, it will need to be determined by testing the setup.

  6. Enter the command in the String field.