I am using a linear stage with 9512+7610 combo. The stage have two limit switches (as usual) and a linear encoder. I have an issue with one of the limit switches, which is on the negative direction of the encoder, so I call it reverse limit. The problem is very strange: the 9512 unit ignores the switch when the motor is enabled. This means, when I turn it with hands and hit the switch, the controller responses correctly; but when it drives the motor toward the switch, it go all the way to the hell until I disable the driver. As soon as the driver is disabled, it realizes the switch is on, and hold the motor. At the same time, the forward switch works as expected, stops the motor as soon as it is active. The engineer of the stage ensures me that both switches should act the same electronically, only the reverse switch is higher in mechanical precision. Both switches are connected to a common ground, so I used sourcing output setting for both on the 9512.
To further diagnose the issue, I measured the voltage on the switch. Strangely, both switches seems to be working as expected: 0 V when not active, 11.6 V when active. However, for the limit switch, even I can see the voltage jump from 0 to 11.6 when it becomes active, the controller just totally ignores it: even the 'limit' LED on the unit does not light up. I also tried to switch the forward and reverse switch on the wiring, and still, the forward (working one) still works on the reverse port, and the reverse (not working one) act the same on the forward port.
I know this is a very confusing problem, so any suggestion or speculation is welcome. Thanks!
