How To | Testing External Control Protocol (ECP) commands with Telnet

Understand how to use Telnet to test External Control Protocol (ECP) commands.

Updated at May 9th, 2023

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Testing ECP commands with Telnet is a useful tool. If you are having issues controlling Q-SYS with a third-party control system, testing with Telnet can help pinpoint where the issue is. For example, if you can successfully connect to a Q-SYS Core processor over Telnet and send commands, then you are likely dealing with an issue related to the third-party control system.

To test ECP commands over Telnet, you must first turn on the Telnet Client on your computer. To do this, follow these steps:

  1. Open the Control Panel.
  2. Click on Programs.
  3. Click on Programs and Features.
  4. Click "Turn Windows features on or off".
  5. Scroll down the list of Windows features and select the Telnet Client box.
  6. Click Ok.

At this point, you can initiate a Telnet session in the Command Prompt and start sending commands to your Core. To do this, follow these steps: 

  1. Open a Command Prompt by pressing the Windows key and typing "cmd" and then Enter.
  2. Type "telnet <CoreIPAddress> 1702" and press Enter. This will initiate the Telnet session.

You can now start entering ECP commands and should receive a response for each one. See the screenshot below for some examples of sent commands along with their responses (using a Gain control and a Mute control called 'gain' and 'mute', respectively).
You can also test ECP commands using Telnet in emulation mode. To do this, repeat the same steps as above, but once the telnet session is open, type "open localhost 1702" in the Command Prompt.

For more information, refer to the External Control APIs section of the Q-SYS Help.