If this is the first time you have connected to your coder, refer to How do I connect my phone to the coder?
If you have previously connected to the coder but can no longer connect, you need to ensure that there are no other phones are connected to the coder.
You can verify if another phone is connected to the coder if the blue connection light on the coder control panel is illuminated.
For a complete explanation of light locations on the Marsh 241D Coder HMI, please access our Document Library - just Sign In (or Register first, if you haven't already) and gain access to a wealth of support documentation and guides including the M241D HMI Guide .
If there are there are no other connections to the coder, and you are still unable to connect, use the In-App Troubleshooting capability for further assistance.