You can directly connect the DSP5D to a PM5D via standard cascade cables if they are to be used in relatively close proximity. But if you want to use the DSP5D as a powerful stage box the DCU5D Digital Cabling Unit lets you locate the DSP5D as far as 120 meters* from the PM5D console,

connected only by one Cat-5 Ethernet cable (appropriate high-performance cable). The DCU5D converts the PM5D cascade signals (68-pin D-sub connector) to and from Cat-5 audio, dramatically reducing cabling requirements while maintaining solid audio and control reliability over extended distances.