It turns out that this ‘modem not responding’ error is caused by the RX connections not being terminated correctly and the floating signals can then trigger this modem error….

Any unused ports need to be terminated (this only applies if you’re using the 14-way or 18-way cables). The ports can be terminated by adding 120 ohm resistors between the RXA and RXB wires, as per the recommendation in the user manual, or by installing the optional junction box.

If the error is not resolved by following the above, please contact us again.