How can I connect the DA100 to a PC via RS-232C and acquire data continuously? Also, can I synchronize the data acquisition on the software with the scan interval on the hardware?

The set of communication commands TS.GET.FM outputs data on the necessary number of channels (1 scan interval's worth). Accordingly, data cannot be output continuously. Also, the data acquisition on the software has nothing to do with the scan interval on the hardware, so they cannot be synchronized. On the hardware, acquired data is stored in synch with the scan interval (stored data is updated every scan interval). Thus, the data that stored at the moment the communication command TS.GET.FM is sent, is output.