• Check the input LEDs. Any ON will hold the gate open and indicates a problem with a keying device. Exception is “STOP”.
• Check the external safety devices. Any activated safety devices will hold the gate open and indicates a problem with the safety device.
• Check limit LEDs. If both LEDs are simultaneously lit, it indicates both open/ close at same times. Check limits for failures. Replace as necessary.
• Check the loop detectors. Any activated safety devices can hold the gate open and indicates a problem with the loop detector or ground loop.