TTY Module: This housing includes circuitry required to convert Baudot codes from the TTY Device to CTM for transmission over the digital GSM network.
Cable: 1/2 meter long cable connects the TTY Module into the bottom connector of the Siemens GSM cell phone handset.
Note: The TTY Cable is compatible with the following Siemens handsets only: Siemens A56, CT56, C56, S55, S56, SL56 and M55 and M56.
The TTY device is a pre-existing unit, not sold here, used for telephone communications by the hearing disabled. This unit is typically used for communications via the landline telephone network. Output from the TTY device is an analog signal. This analog signal is not compatible with digital wireless devices, thus the need for this TTY conversion cable.
The TTY Cable connects TTY devices and converts Baudot code to a code that is compatible for GSM cellular networks (CTM).