Please do refer to the module datasheets to figure out the correct state that the serial lines the DIP switch provides access to need to be tied to for the different modes. The DIP switch does nothing special but provide a convenient way to configure the relevant pins of the modules to VCC/GND.
For example, take DIP 2, PORTSEL. The AP2 module datasheet. in Section 1.2 will tell you what PORTSEL is, and that you need to tie it to GND for Async mode and VCC for Sync mode. Furthermore, the schematics in section 1.3 of the module datasheet will tell you what the connections in the module need to be for the different serial modes.