This Module is a prototype or in a concept phase.
Midi / USB / control outputs for trigger sequencer A-157
It offers the control signals Start, Stop, Reset and Clock as outputs so that the A-157 module combo can be used as master for other devices (e.g. A-154/A-155, another A-157 or other sequencers). It also connects the A-157 to Midi (in and out) and USB.
Doepfer will be demonstrating the A-157-4 at the Superbooth 2018 controlling the instruments of a Roland TR-8 via Midi or USB.
http://patchpierre.blogspot.fr/2018/05/doepfer-157-4-module-trigger-sequencer.html