Mitsubishi C70

IV - 95
Appendix 7. Explanation of Alarms
Appendix 7.4 MCP Alarms (Y)
Y20 Output OFF check error (PLC side) 0050 (Unit No.)
Details
Although the output OFF check function turned OFF the dual signal module’s output signals,
there is a feedback input signal which is staying ON.
Remedy
The PLC side output transistor may be broken. The No. of the error module is displayed.
Replace the dual signal module.
Carry out the output OFF check to confirm there is no problem.
Y20 Output OFF check error (NC side) 0051 (Unit No.)
Details
Although the output OFF check function turned OFF the dual signal module’s output signals,
there is a feedback input signal which is staying ON.
Remedy
The NC side output transistor may be broken.
The No. of the error module is displayed.
Replace the dual signal module.
Carry out the output OFF check to confirm there is no problem.
Y21 Speed obsv signal: Speed over 0001 (Axis name)
Details
The speed exceeds the safety speed limit when the "speed monitor mode" signal is ON.
The name of the axis with an error is displayed.
Remedy
Decelerate the speed to reset the warning and start the speed monitor.
Y21 Dual signal: State after error unconfirmed 0020 (Device No.)
Details
- A dual-signal comparison error was detected.
Signal outputs from both PLC and CNC CPUs have not been confirmed since the power
was turned ON again.
The No. of device from which the signal output has not been confirmed is displayed.
When several signals have not been confirmed, the smallest device No. will be displayed.
Remedy
- Remove the cause of the dual-signal comparison error, turn the controller OFF and ON,
then turn the signal ON and OFF in the dual-signal comparison state.
- The dual signals with the error can be reset and canceled if not used.
Y51 Parameter G0tL illegal 0001
Details
The time constant has not been set or exceeded the setting range.
Remedy
Correct "#2004 G0tL (G0 time constant (linear))".
Y51 Parameter G1tL illegal 0002
Details
The time constant has not been set or exceeded the setting range.
Remedy
Correct "#2007 G1tL (G1 time constant (linear))".