> 3.1.6 | Relationship between Multiplex Channels and Non-multiplexed Physical Interfaces

> Table 2 summarizes the allocation of non-volatile and user profile settings to the various multiplex channels and non-multiplexed physical interfaces. This allocation scheme shows where stored settings take effect when switching from multiplex to non-multiplex mode and vice versa. See chapters below for further detail.

> Table 2: | Allocation of virtual channels to physical interfaces

> Physical interface | ASC0 | ASC1 (if available) | USB (if available)
> Corresponding multiplex channel | Multiplex channel 1 | Multiplex channel 2 | Multiplex channel 3

> 3.1.6.1 | First Serial Interface ASC0

> ASC0 and the multiplex channel 1 are using the same parameters, and thus, the same user defined profile (if any). As a result, non-volatile settings and a user profile stored on multiplex channel 1 will take effect on ASC0 after closing the multiplexer and switching to the physical interface ASC0. Likewise, non-volatile settings and a user profile stored on ASC0 will be loaded on multiplex channel 1. See also note on AT&W in Section 3.1.4.

> 3.1.6.2 | Operation of a Second Physical Serial Interface ASC1 (if Applicable)

> This chapter applies only to Siemens GSM modules equipped with a second physical serial interface (referred to as ASC1).
> ASC1 is disabled when the multiplexer is enabled on the first serial interface ASC0. Yet, both ASC1 and the multiplex channel 2 are using the same parameters, and thus, the same user defined profile (if any). As a result, non-volatile settings and a user profile stored on multiplex channel 2 will take effect on ASC1 after closing the multiplexer and starting up ASC1. Likewise, non-volatile settings and a user profile stored on ASC1 will be loaded on multiplex channel 2. See also note on AT&W in Section 3.1.4.
> This may be a problem when ASC1 is not connected, but flow control (for example AT\Q1 or AT\Q3) is stored to the user profile on the multiplex channel 2. In this case, flow control takes effect on ASC1, when the multiplexer is switched off. If then for example a large amount of URCs is generated, their transmission might be stopped due to the flow control. To avoid this problem we recommend that you do not activate flow control on multiplex channel 2 when setting up a user profile with AT&W.

> 3.1.6.3 | Operation of the USB Interface (if Applicable)

> This chapter applies only to Siemens GSM modules equipped with a USB interface, for details refer to [1].
> ASC0 and ASC1 are disabled when the multiplexer is enabled on the USB interface.
> The USB interface and the multiplex channel 3 are using the same parameters, and thus, the same user defined profile (if any). As a result, non-volatile settings and a user profile stored on multiplex channel 3 will take effect on the USB interface after closing the multiplexer and starting up USB. Likewise, non-volatile settings and a user profile stored on the USB interface will be loaded on multiplex channel 3. See also note on AT&W in Section 3.1.4.