> Even though it's unlikely it could fail. Commercial drives use to have a safe > torque off input. I expect it work for AC motors but if a DC motor is > overloaded semiconductors usually fail with short so it could run at full > speed > in one direction even if control signals are turned off.
The HP_UHU DC Servo drives track the encoder verses input pulses. So if the motor goes off and exceeds the tracking error a fault is generated. The board has a coupled FAULT_OUT/IN circuit so that when one motor faults it pulls down the fault line (Open Collector). Since the other drives are also connected to this same signal a fault from one drive takes the whole works down. The problem with the HP_UHU drives is that once faulted they need to be reset or lowvoltage power cycled. The interface board I built uses this same enable line to pull the reset signal low for each drive; through an opto-coupler. The STMBL is supposed to be reset by bringing the enable false and then true. But of course if the enable is linked to high voltage power I'm in that Catch-22 situation. No Enable, No high voltage, No high voltage? Then a fault condition. Enable stays low. Must rethink this. > > Most of the time I expect no one is in the danger zone but if it is likely > someone is in the danger zone then emergency is activated it is important it > could be trusted. Misstakes happens but otherwise there is a reason to press > the emergency stop. > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
