Hello,

Have you seen this document
http://www.doepfer.de/pdf/A154_155_Connection.pdf


maybe with this photo you can see better how the different parts are connected
- Blue connections to the bus
- Pink connections for sending a message between modules
- Yellow power connection from one module to another ( attention to the A- 155 S1 must remain free)

http://i56.serving.com/u/f56/17/81/92/13/a154a110.jpg