The WISP has a much simpler C&DH subsystem than the SOM. It has no computer. The command sequencer stores commands in a circular buffer, and executes them continuously. The WISP may receive commands from the SOM; the sequencer acts on these and then returns to executing the commands in the buffer. The SOM may send a command that changes the command sequence.
The data handling circuit collects data from all the instruments, and sends it to the acoustic transducer for transmission to the SOM. Because the instruments are sending back data continually, the data handling hardware interleaves the data in a format decodable by the computer in the SOM.
All of the instruments on the WISP are interfaced with the command and data circuits through an RS-232 serial line. This forms a point-to-point centralized architecture, as seen in Figure 7.