Y+ Limit Tripping Problem

[autotransdesign]

We have a retrofit mill that when homing the machine will trip the Y+ limit switch and will "lock" the servo. It does not do this on any other axis, or Y- limit. When it homes the X axis it will bump the switch and back off, but if it bumps the Y+ limit it will not back off. It also cannot be manually jogged off of the limit. It's just locked up. The only fix we have found is to move/disassemble the limit stop to clear the switch.

Is there a parameter change to fix this? Can the machine be homed in Y- direction? It currently homes X-,Y+.

Thanks.

[AjaxTech]

It most likely means that the limit switches are not wired correctly to the DC3IOB. Is direction reversal turned on for the Y axis? If so, have you followed TB137? Please email a current report from your system to tech@ajaxcnc.com using TB193. Thanks.

[Centroid_Liviu]

TECH SUPPORT
From the main screen press ALT+I to bring up the PLC Diagnostic menu. Manually trip the Y limit switches and verify that input 10 changes state when you trip the positive limit switch and input 9 changes state when you trip the negative limit switch. You can press ALT+I again to get rid of the PLC Diagnostic menu. Also verify that you can jog the Y axis in both directions before homing the machine. If you cannot, swap the motors to see if it's an issue with the drive or the motor.

AUTOTRANSDESIGN
Input 9 trips and self clears for Y-, and Input 10 trips and self clears for Y+. The PLC state shows green for both in normal state, and then red when tripped. The table will jog slowly before homed in all directions X/Y/Z +/-.

TECH SUPPORT
Try manually tripping the Y+ limit and jogging the Y-axis in the positive and negative direction. It shouldn't allow you to jog in the positive but allow you to jog in the negative direction.

AUTOTRANSDESIGN
We really appreciate all your help. We figured out what was wrong. The wires were backwards at the PLC. I flipped the wires and the inputs and it now works properly.