HOME / Q & A / About Controller / 1.Alarm Troubleshooting

●Questions about Y Axis

Ans .

Please reset the Y axis Home position as video :  


Step : 

  1. Press Home key to switch to Home mode
  2. Press F6 Param setting key
  3. Press F7 Serial Tuning
  4. Enter the password 
  5. Press F1 OK
  6. Press F7 Abs Home setting
  7. On X,Y,C axis Home setting screen , move Yellow cursor to Y
  8. Press F1 Home OK
  9. Y axis Home OK shown on screen.
  10. Finish the Y axis Home reset procure.

Execute Y axis Home again. 

Please confirm the ram was stop at top safety point and door is closed before execute Home.

The top safety point is to avoid the crush accident happen when the user to execute Home while slotting bar at inside hole of workpiece.                           

How to stop Ram at top safety position: 

Switch MPG mode , press Ram Run button , then press Ram stop button , Ram will stop at top safety position automatically.

Ans .

When alarm inform the Home position is different from original Y home position. 

Please check Y axis Home position again. 

After adjusting the sensor signal position, the Y axis Home position will change 5mm (one pitch of ball-screw) .

For example, the original is 93%, if customer adjusted the sensor position to next circle 59%, the Y axis Home position will be different from original Y zero position, and the different distance is one pitch 5mm.

  • If had adjusted the sensor to next encoder circle, it needs to double check:
  1. The machine Zero (Home) position
  2. The first-Y setting value.


  • Please do it as instruction:
  1. Use caliper to measure Y position after execute Y home position
  2. Use MPG to check the Y axis new position is forward or backward .
    Please use MPG to move the Y axis at work piece center
  3. Press F6 parameter
  4. Press F5 Go to parameter
  5. Enter 882 , then the password , the 882 show the “ Y axis Home offset setting value , please write down the original value.
  6. Use the value to add the new Y axis absolute value
  7. Input new value to 882
    * Please note:
    if MPG value is -5.000 , must use original value to deduct 5000 (unit :0,001mm) 
    if MPG value is +5.000 , must use original value + (plus) 5000
  8. After set the new Y axis Home offset value, then need to Execute Y axis Home (zero return) again to let Y axis Home position at right position.

Video of how to check the sensor and Y axis home position: https://www.dropbox.com/s/3zma1rjqddz6b71/Adjustsensor%20%26%20Y%20Axis%20zero%20retum.mp4?dl=0


Ans .

Two possible reasons to caused ALE01, the over-current alarm:   

  1. U,V,W power cable damaged or happen some problem to cause short current and over current.

   Please check the Y axis power wires (Uy,Vy,Wy) .

  1. If the Y axis Uy,Vy,Wy power wires OK. → possible the Y axis servo driver damaged .


How to test Y axis power cable problem or Y axis servo driver problem.

The X axis servo driver and servo motor is same as Y axis servo driver and servo motor, so we can connect Y axis’s to X axis’s for testing, please follow :

  1. Turn off power, open electric box .
  2. Take off X axis power wires Ux,Vx,Wx and Y axis power wires Uy,Vy,Wy
  3. Connect X axis power wires Ux,Vx.Wx  to Y axis servo driver 
  4. Connect Y axis power wires Uy,Vy,Wy to X axis servo driver 
  5. Change X axis encoder connector to Y axis servo driver CN2 
  6. Connect Y axis encoder connector to X axis servo driver CN2. 


The checking what happen:

  1. If Y axis servo driver damaged: Y axis servo driver will show ALE01 again.
  2. If Y axis servo driver no problem: Y axis servo driver will show 0 (normal), and ALE01 alarm go away.
  3. If X axis servo driver show ALE01: Y axis power cable Uy,Vy,Wy , wire have problem.
  4. If X axis servo motor show 0 (normal): Y axis power cable Uy,Vy,Wy is OK.


NOTICE: Don’t move X axis during the test period and change these wires and connector back to right position.  

Ans .

ALE-06 is overload alarm.

Please take out Y axis servo motor cover to check the Y axis movement by manual driving good first, then check if is the Y axis servo driver or Y axis servo motor have problem.


Possible reasons for ALE-06 alarm:

  1. The mechanism happen trouble:
    Such as ball screw not run smoothly, or any obstacle stop at Y axis slideway caused Y axis servo motor overload. 
    If is this reason, the alarm will go away when turn off power then turn on power again. But alarm ALE-06 will come out after use MPG to run the Y axis .
  2. Y axis servo driver happen problem:
    If turn off power then turn on power again, but ALE-06 still shown on Y axis servo driver LED screen, it means the Y axis servo driver happen problem.


Please follow the step: 

  1. Turn off power and open electrical box.
  2. Turn on power under the door of electrical box is open. 
  3. Check alarm No. shown on Y axis servo driver LED screen.


CNC-300/350 use the same servo motor & servo driver for X axis and Y axis.

So could use the one of axis from X or Y ‘s servo motor and servo driver to test the other axis ‘s is no problem.


If want to check the Y axis as example:

Make sure the X axis servo motor and servo driver is OK first, then connect the X axis ‘s to Y axis’s as following.

This method does not make short or damaged any driver or servo motor.

If Y axis servo driver no problem → Y axis servo driver do not show alarm.

If Y axis servo driver damaged → Y axis servo driver show same alarm No.(As 6-1.)

If Y axis servo motor damaged→ Connect Y axis damaged servo motor to X axis servo driver, X axis servo driver will show alarm message. (As 6-2.)


Procedure as following:

  1. Turn off power and open electric box, to find the Left one is X axis servo driver and middle one is Y axis.
  2. Change the Y axis servo driver U,V,W wire (Uy, Vy, Wy) to X axis servo driver U,V,W s (Ux ,Vx, Wx)
  3. Connect U,V,W of X axis servo driver (Ux,Vx,Wx) to Y axis servo driver .
  4. Change Y axis servo driver encoder connector to X axis servo driver CN2position.
  5. Connect X axis servo driver CN2 connector to Y axis servo driver CN2 position.
  6. Turn on power and check what shown on LED screen of X axis and Y axis servo driver:
    6-1.If Y axis servo drive still shown alarm on Y axis servo driver→confirm Y axis servo driver have problem .
    6-2.If X axis servo driver shown alarm No. on LED screen→ confirm Y axis servo motor damaged and caused the problem.

After sure the damaged part , please change back to x axis’s Ux VX, Wx , CN2  to X axis servo driver .Uy, Vy, Wy and CN2 of Y axis connect back to Y axis servo driver .


Alarm 029Y is related to the index of Y axis servo motor encoder.

Please check the Y axis servo motor operate is normal first , and :  

  1. Press F7 (Diagnosis) on main screen,
  2. Press F2 Data system to enter No. 49 parameter, normally No.49 will change pulse well.
  3. Check if NO. 49 is change value during Home Y process ?
    Or it will increase or reduce 10000 when rotate one circle by MPG function? 
    If the value of NO. 49 is changing correctly, that Y axis servo motor encoder is normal.
    If the value of NO. 49 no changing during Home Y process or moving Y axis by MPG, two possible reasons, please check it:
    3-A. Encoder of Y axis servo motor happen problem
    3-B. Signal cable (wire) happen problem.
  4. Open the electric box and double check the Y axis servo motor driver signal connector CN1/CN2 was connected well or any loose?
  5. Check the servo motor end connector is loose or not?


  • *If the above instruction does not find and solve the problem, suggest informing the following information for engineer to help solve the problem:
  1. Result when worker do Y axis zero return (Home Y), the alarm screen photo.
  2. Alarm history at period machine happen problem


Normally, Y Home sensor red light on only during Home dog go to sensor under executing Y axis Home period. 

If sensor always ON or always OFF, its abnormal, two possible reasons causing it:

  1. The sensor was damaged : 
    Find the sensor and use screw-driver to touch the top of sensor , when screw-driver touch sensor, the sensor ON, leave sensor, sensor must to be OFF.  
    The test distance from sensor is within 4mm.
  2. The sensor distance is too near to Y axis slide way : 
    It may less 4mm so sensor always ON, please  move the sensor position a little bit lower.


Video for how to check the sensor : 



After adjust or replace new sensor : 
Press F7 diagnosis , then press F2 system data to check percentage show on NO. 57 (Y axis sensor Home signal percent) Normal range is 50%+-20% (30~70%) , best is 50%.

If the NO. 57 over 80% , the control unit will issue alarm , need adjust /tilt  the Y axis sensor left or right and check NO. 57 value until it on normal range .


Alarm 95 is for check Y axis Home sensor position is at servo motor encoder safety range 20-80%, the purpose is for Home position stable.

When it appeared, it means Y axis Home sensor send the signal to control unit it is not at 20%-80% safety range.

When execute Y Home process, controller ask servo motor moves front (Y-direction) to search for Y Home sensor, then Y sensor send back a signal , controller will check the position is at Y axis servo motor encoder percent.

For Y axis servo motor, one circle is 100 percent and it has a basic zero reference point. The Home signal has +-5% tolerance, in order to avoid the Home position unstable, we don't let Y Home sensor at the 0-20 percent or 80-100 percent.


How to adjust the Y axis Home sensor at 20-80 percent position?

  1. Find out Y axis Home sensor.
  2. Two sensors at Y axis slide way side:

First on the front which near operator is Y- Hardware limit sensor.

Second one which near the machine column one is Y Home sensor.

  1. Please loose the 2 M3 screws of Y home sensor a little
  2. Then tilt sensor left or right a little to adjust , until it is at safety range.
  3. Execute Y Home again.

If alarm go away, it means Home sensor signal is within 20-80 percent.

  1. Also, worker could press main function to adjust and check:
  2. -1.Press F7 Diagnosis
  3. -2.Press F2 System data to enter No.  57
  4. -3.No.57 is for Y axis signal data, the Home signal percent show on it (NO. 56 is for X axis; NO. 59 is for C axis rotary table).
  5. -4.Checking the No.57 valve
  6. -5.Adjust Home sensor and press Y Home again to check the percent.  
  7. -6.Repeat this process until the Y axis Home percent at safety range.

*Safety range on 20~80% .

  Better range is on 30-70%, the best value is 50% .


Besides the reason of 20 %~80% safety range, the other it's possible the Y axis Home position change.

Please check if the original Y axis Home position change or not , Go to parameter 882 (Home Offset setting) to adjust the Y axis Home position.

If it change , normally it just possible change one pitch (5mm) .

But if the Y axis Home position no change, then don't need to adjust parameter 882.