The tooling interface will define the versatility of the device. The details of the interface wiring is actually quite simple. There will be power wires and signal wires.

The power wires can be a fixed AC/DC or varying voltages. They can have specific current characteristics. The issue that matters is how does one ensure that the right power lines are used for the tool. This can be accomplished with incompatible plug types which prevent inadvertent wiring (Lean Six Sigma : Poka-Yoke). The method is dependable but can get quite cumbersome and complex as every possible power hookup is implemented along with a unique plug. This can be reduce in scope by implementing standards such as all tools use the same voltage and are within an amperage limit. Another approach would be to have the tool posses an encoded output that informs the tool holder what power spec should be applied. This approach makes the tool self-descriptive and the tool holder smart. The complexity goes up from multiple dumb plugs to a minimal number of smart power lines and a communication interface.

Signal lines carry the same complexities as the power lines. Signals can be binary digital, analog, wave shaped and encoded forms of the previously mentioned types.

Answering the issues with the interface would normally be handled by developing an interface standard. And that is what is going to happen. There are obviously standards already out there, so reinventing the wheel is not necessary. That means research. I will start with some PLC research and get back to you all. (It is late, forgive the grammar.)