Q: The GSK 980TD alarms for ESP(Emergency Stop Signal), when the spindle speed reaches 1000 RPM or above, why?

A: The ESP switch could be open circuit due to the vibration of the high speed, check the connection and fix it.

GSK980TDb Specification:

http://www.cncmakers.com/cnc/controllers/CNC_Controllers_for_Lathes/GSK980TD.html