Originally Posted by
SCzEngrgGroup
Not sure why you'd say that.... That is how they're designed to be used. Those are opto-isolated inputs. To make them work, you have to drive current through the LED from DIR+ to DIR-, as indicated in the legend next to the connections on the driver. This can be done by either tying DIR+ to +5V, and grounding DIR-, or by tying DIR- to GND, then pulling DIR+ to +5V. In most cases, as apparently here, DIR+ will be tied to +5V, and the BOB will drive DIR- to GND using a TTL gate or transistor. For testing purposes, there is absolutely nothing wrong with disconnecting the wire from DIR-. then forcing DIR- to GND as I suggested, and it will certainly not create any "crazy effects".
The signal in Mach3 must be configured as ActiveLow. If the Tormach Mach3 configures those signals as ActiveHigh, that could explain the whole problem, as the way Mach3 drives the DIR signal, if the polarity is set wrong, the steip pulse can occur when DIR is in the wrong state.
Regards,
Ray L.