ALARM - Y Motor Alarm


Hello, On the initial setup of my Optimum BF46 Milling machine, I stupidly managed to snag and damage the cable going to the Y Axis Servo Motor (Clearpath SDSK-3421S-ELS) and the Masso Came up with "ALARM - Y Motor Alarm". I replaced the entire cable and Plugs and the Masso Came up with "ALARM - Y Motor Alarm" again. The Y Axis Servo Motor Auto tunes (through Clearpath Software) without a problem. I swapped the Servo Motor from the Z Axis to the Y Axis and still the same problem "ALARM - Y Motor Alarm". The only thing I can think of is that I might have damaged the Masso. I might need to send it back to Masso for a check up.

Any Ideas out there. I could really use the help.




MASSO Support
Staff member
Hi George,

Sorry to hear about the mishap. Just need to clarify what you did to test.

When you said you swapped the Z axis motor and the Y axis motor was it just the motor you swapped or the motor and drive? I would imagine it is most likely that it would be the drive that would be damaged rather than the motor or failing that possibly the encoder on the motor.

If you think you damaged the input on the Masso then move the Y motor alarm to a different input and see if that solves your problem. If the input is damaged then it will be the opto isolator which can easily be replaced by the user.

Does the alarm occur before the axis starts to move or after it has moved some distance?

If the Y axis moves does it move in both directions before you get your alarm?

On the F1 screen are you seeing the Y axis alarm input as low before the axis moves and does it change to high when you get the alarm?

The answers to these questions should help narrow down where your problem is.




Hello Peter and thanks for your prompt assistance.

I swapped just the motor as the drive pulleys and belt were not damaged. I believe only the cable or plug was damaged and shorted.

I don t think the Encoder is damaged as the Servo Motor still auto tunes with the Clearpath software. Also, I removed the Z Axis Servo Motor and swapped it with the Y Axis Servo Motor and still had the same fault.

You asked if I could move the Y motor alarm to a different input. Which is the Y Motor Alarm input? I have wired my Servo Motors the same as shown in your Manual in the Clearpath Section. Could you please let me know which wire I need to change? Is it the HLFB- wire as it is the only input wire from the Servo Motor?

The Alarm occurs as soon as I depress the Safety Stop button and I cannot move the Y axis at all.




Maybe you by misstake have assigned one of the inputs to y motor alarm. Scroll through your inputs on F1 screen and check if any input is setup to trigger this alarm.