Code 701009: Monitoring, brake 4th axis! Relay defective! (do not switch off machine)

The monitoring function for the "4th axis brake" actuation has responded. At least one relay for activating the 4th axis brake is defective. Error messages Axes (>Z) Monitoring, brake 4th axis! Relay defective! (do not switch off machine) This monitoring occurs when the brake is released and clamped. Error while releasing the brake: Actuation "Release 4th axis brake" is registered, but the PLC input signal "4th axis brake monitoring" is still signalling. As soon as the brake has been released, the PLC input signal "4th axis brake monitoring" must signal the signal state [0]. Error while clamping the brake: Actuation "Release 4th axis brake" was cancelled, but the PLC input signal "4th axis brake monitoring" is not signalling. As soon as the brake is no longer released, the PLC input signal "4th axis brake monitoring" must have the signal state (1). The "release 4th axis brake" actuation remains pending and the axis is kept under control. For safety reasons, it is no longer possible to unlock the protective doors. NOTICE! Attention! The machine control must not be switched off. There is the danger that the brake is no longer holding reliably and the 4th axis could fall over. There is a danger to the machine! 1. Switch to manual mode. 2. Move the 4th axis to a position where the axis can't tip over (e.g. 0° position). 3. Switch off the machine control. Protective door is unlocked with a delay of 10 seconds. 1. Check the PLC input signal "4th axis brake monitoring" and the "Release 4th axis brake" actuation. 2. Check the relay (optocoupler) for actuating "Release 4th axis brake" and exchange, if necessary. 3. Once the malfunction has been eliminated, switch off the control with the [Control OFF] key. 4. Turn on the machine control with the key [Control ON]. Message is cleared. Check the brake activation: