> 3.2.2 | Escape Sequence

> When the multiplexer protocol is active only coded data is transmitted over the UART. The coding includes a header and a checksum. Therefore, the direct parsing of this sequence is not possible. An escape signal might be undetected because the decoded time relations may be disturbed.
> The following transmission path for the ESC signal has been implemented:

> • | DTR is transported within the logical channel. To terminate a call, the normal way of using DTR is available. Keep in mind that the multiplexer cannot transport this signal in real time. Please use a certain gap time between signaling with DTR.

> • | It is possible to detect “+++” on the customer multiplex application and transport this information via the MSC signal to the module (see Section 4.3.9).

> • | As an alternative, ATH may be sent on one of the other channels, for more detailed information please refer to [2].