Cause:

• The last concentrator in the chain is not terminated.

• There is a problem with a cable, one of the modems, or the phone line.

• The timing is set incorrectly.

• The host adapter is malfunctioning.

Solutions:

• Terminate the last concentrator on the chain.

• Verify that the cables are good, that the TxD light on the remote modem is lit, the RxD light on the local modem is lit, and that the phone lines are good.

• Check to make sure the timing is set correctly on both the adapter and on the concentrators.

• Run the appropriate diagnostics on the host adapter.