We ripped out all of the control wiring for the TC (and everything else on the machine for that matter). There are only 2 solenoid valves that control the TC, one for the clamp, and one for the arm. This machine had 2 additional solenoid valves that I think controlled the speed of the arm in various parts of the cycle, those came out also.
The solenoid valves are maintained position valves, and only require a 200ms pulse to shift. Not the best control scheme, but it works. There are 4 switches that are important, the arm in position limit switches (spindle and tool), and the clamp open & closed pressure switches. There is one additional limit switch that reads some mid-position of the arm, not useful in this application.
We used small PLC relays with low current, 24VDC coils to interface with the Galil controller. The relays are also available in a 5VDC coil depending on your needs. All of the control code is in the Galil controller. As soon as I figure out how to do it, Mach3 will send a tool change request to Galil, and Galil will fire back a ''OK, I'm done'' message when the tool change is complete.
I think your KFlop has the same capabilities as the Galil, it just programs in C or C++ rather than DMC code.
The relays are the little black modules on the panel, these are in banks of 4 relays. Only 4 are used for the TC. The red solenoid valves control the TC, the other 3 valves control the spindle brake, the power drawbar, and the one on the lower right dumps the air pressure to the TC manifold on E-stop.