Module A-115 is a four-way frequency divider. The frequency of a signal at the input is halved (half frequency = first sub-octave), quartered (1/4 frequency = second sub-octave), and so on. In this way, the DIVIDER produces four sub-octaves (F/2 down to F/16).
At the output, the A-115 produces a summed mix of the original and the four sub-octaves. There are attenuators to control the amount (ie. Amplitude) of the original signal and each of the sub-octaves.
Bear in mind that the sub-octaves output by the A-115 are all true square waves. At the output there are always four square waves and the original signal available.

For more detailed information please look at the English user's manual A115_man.pdf

Note: The new version of the A-115 (V2 2008) has an additional 3-terminal pin header with associated jumper available. JP3 at the top of the pcb (labelled "Source #1") is used to select if the original signal (i.e. the unchanged input signal of the In socket, not converted into rectangle) or the rectangle signal (derived from the input signal) is used for the Orig. control. In the left position of the jumper (towards the front panel) the unchanged original signal is used. In the right position the derived rectangle is used.
In addition another jumper "JP2 AC/DC" is available which is defines the type of output coupling. When JP2 is installed the output is DC coupled. This version is normally chosen when the module is used for dividing sub-audio signals (e.g. with LFO as input). When JP2 is removed the output is AC coupled. This is normally used for audio signals because then the output signal has no DC offset voltage.