- The concentrator is not getting the initial signal from the host adapter because it is not connected at all, or it is connected on the wrong line.
- The driver is not installed or the concentrator that is configured does not match the actual physical concentrator type.
- The timing on the host adapter and/or the concentrator and/or the modems is set incorrectly.
- The host adapter is malfunctioning.
- Verify that the cables are all connected securely and that the concentrator is attached to the correct line.
- Check to make sure that the Operating System has been updated with all Service Packs/patches installed, the latest version of the Digi adapter driver is installed and loading correctly, and that the correct type of concentrator is configured.
- Verify the timing settings on the host adapter, the concentrator, and the modem.
- Run the appropriate diagnostics on the Digi adapter for the card and bus type.
Mar 22, 2019