If the Manual Fine Probing check box is selected, then when a manual probing point is taken, the controller automatically switches to DCC mode while moving away from the part in order to use the normal deflection probing cycle. This may result in slower manual probing but improves accuracy.
While recent machines with analog probing systems may support Manual Fine Probing, not all analog probes/controllers support this mode of manual probing. In those cases, PC-DMIS ignores this check mark. Your CMM controller's manufacturer will know if your controller supports this option.