ANti corner dive in Mach3 has an On/OFF control AND you can set teh level at which it kicks in as a percent of feedrate. IF you set teh level at 80% then when teh Combined Vel in Mach3 slows to a level of 80% of teh called feedrate it should LOCK out the thcdown motion. When the Comb Vel gets back above 80% it releases teh lockout and THCdown can work again.
Ok that is fine, the MiniTHC has an input to lock the THC, so that could easily be connected via the AntiCorner Dive I think
Hood
See this is what happens when we're sloppy with terms.
Remember Hood that you're using the CSMIO. Anti-dive in "Mach" is like all the other THC functionality, it's in the Parallel Port driver/pulsing engine. How it works and how it's configured is completely irrelevant to you. You need to find out how the CSMIO (anti-dive in this case) works and is configured and what (if any) external signals or control functions it has.
Remember this has NOTHING to do with Mach or the plugin that allows Mach to communicate with the CSMIO. All and any THC functionality will be in the CSMIO's firmware. It's THAT you need to find out about.