The FANUC SV0413 alarm indicates an axis LSI overflow. This alarm occurs when the position deviation counter overflows and the value exceeds the register range.
In normal operation, the command value and the feedback value should be almost the same. The value in the error register is generated by subtracting the feedback value from the command value, so the position deviation normally remains close to zero.
However, if the command value and feedback value are in opposite directions, or if only one side continues to change while the other side does not change properly, the value in the error register will continue to increase. Once the value exceeds the allowable range, the CNC system generates the SV0413 alarm.
What Does FANUC SV0413 Alarm Mean?
SV0413: Axis LSI Overflow
The FANUC SV0413 alarm means that the position deviation counter has overflowed. The deviation value has exceeded the register range, which is caused by an abnormal relationship between the command value and the feedback value.
Under normal conditions, the CNC command and axis feedback should correspond to each other. If the command and feedback move in the same direction and the feedback distance is correct, the position deviation remains within a normal range.
If the command and feedback directions are opposite, or if the system outputs only a command without actual feedback, or receives feedback without a corresponding command, the position deviation counter may continue increasing until an overflow occurs.
Common Causes of FANUC SV0413 Alarm
The most common causes of FANUC SV0413 axis LSI overflow alarm include:
1. Command and Feedback Directions Are Opposite
One common cause of SV0413 is that the command direction and feedback direction are opposite.
In this condition, the machine may have command output and feedback input, and the feedback distance may appear normal. However, because the directions are opposite, the position deviation value increases instead of being corrected.
This issue is often seen on gear machines and some machine configurations where spindle or axis direction control is related to gear direction, spindle rotation direction, or special positioning control.
2. Only Command Output Exists Without Actual Feedback
Another possible cause is that the CNC system outputs a command, but the actual feedback does not change correctly.
In this case, the command value continues to change while the feedback value does not follow. As a result, the position deviation counter keeps increasing until it exceeds the allowable register range.
This may be related to machine operating conditions, function settings, peripheral hardware, or feedback signal problems.
3. Feedback Exists Without Command Output
SV0413 may also occur when feedback is detected even though there is no corresponding command output.
This type of condition may occur in certain special machine configurations, such as vertical lathe CF axis control. If feedback continues to change without a matching CNC command, the system may detect position deviation accumulation and generate the axis LSI overflow alarm.
4. Special Gear Machine or CF Axis Control Configuration
This alarm is commonly found on gear machines and vertical lathes using CF axis control. These machines may have special relationships between spindle rotation, axis command, feedback direction, and control mode.
For this type of machine, the troubleshooting direction should focus on whether the command and feedback directions are consistent, whether the operating mode is correct, and whether the control axis handling method is suitable for the current machine configuration.
How to Troubleshoot FANUC SV0413 Alarm
When troubleshooting the FANUC SV0413 alarm, the key point is to confirm the relationship between the command value and the feedback value.
You may need to check:
- Whether the machine has both command output and feedback input
- Whether the command direction and feedback direction are the same or opposite
- Whether the feedback distance is normal during machine operation
- Whether only command output exists without actual feedback
- Whether feedback exists without command output
- Whether the machine is a gear machine or uses special gear-related control
- Whether the machine uses CF axis control, especially on a vertical lathe
- Whether spindle direction commands such as M03 and M04 affect the alarm
- Whether control modes such as G70.5 and G70.4 affect the alarm
- Whether parameter bits such as 3706#6 and 3706#7 need to be switched according to the machine condition
- Whether the programming method is suitable for the machine configuration
- Whether control axis removal is required for a special control condition
Because SV0413 is directly related to command and feedback consistency, it is important to check the actual machine behavior instead of only checking the alarm number. The command direction, feedback direction, and machine control mode should be confirmed together.
Recommended Solution
The correct solution for FANUC SV0413 alarm depends on whether the problem is caused by opposite command and feedback directions, missing feedback, unexpected feedback, or a special machine control configuration.
1. Confirm Command and Feedback Direction
If the machine is running normally and both command and feedback are present, first confirm whether the command direction and feedback direction are opposite.
If the feedback distance is normal but the command and feedback directions are reversed, the position deviation counter may continue to increase and cause the SV0413 alarm.
In this case, according to the machine condition, it may be necessary to switch parameter 3706#6 and 3706#7, switch spindle rotation commands such as M03 and M04, switch control modes such as G70.5 and G70.4, or adjust the programming method.
2. Check Whether Command Exists Without Actual Feedback
If the machine has command output but no actual feedback, check the machine operating condition, related functions, and peripheral hardware.
This situation means that the CNC command value continues to change, but the feedback value does not follow correctly. The cause may be related to feedback signal loss, mechanical non-response, function status, or external hardware conditions.
The feedback system, machine running status, and peripheral hardware should be checked carefully before changing parameters.
3. Check Whether Feedback Exists Without Command Output
If feedback exists without command output, the system may detect position change even though no corresponding CNC command is being issued.
This may happen in certain CF axis control applications, especially on vertical lathes. In this case, the control axis removal function may need to be used according to the machine control requirement.
4. Check Gear Machine and CF Axis Control Conditions
Because SV0413 is commonly seen on gear machines and CF axis vertical lathes, the machine control type should be confirmed early in the troubleshooting process.
For gear machines, check the relationship between spindle rotation direction, feedback direction, gear mode, and program command. For CF axis control, check whether the feedback and command relationship matches the intended control method.
5. Try a Suitable Programming Method If Required
In some cases, changing the programming method may help resolve the alarm when the command and feedback relationship is affected by the machine control mode.
If switching M03/M04, G70.5/G70.4, or related parameter bits changes the alarm behavior, the program command method should also be reviewed.
If your machine shows FANUC SV0413 axis LSI overflow alarm, please contact REACO CNC directly. Our team can help check the command and feedback relationship, gear machine control condition, CF axis control status, parameter settings, and related CNC hardware or configuration issues.
REACO CNC Support for FANUC SV0413 Alarm
REACO CNC provides support for FANUC CNC systems, servo systems, spindle positioning control, CF axis control, gear machine applications, feedback systems, and related CNC hardware issues.
We can help with:
- FANUC CNC alarm analysis
- FANUC SV0413 alarm troubleshooting
- Axis LSI overflow issue analysis
- Command and feedback direction checking
- Gear machine control issue support
- CF axis control troubleshooting
- M03/M04 and G70.5/G70.4 control condition checking
- Parameter 3706#6 and 3706#7 checking guidance
- Feedback system and peripheral hardware checking support
- Replacement FANUC CNC parts supply
If you are not sure whether the SV0413 alarm is caused by opposite command and feedback direction, missing feedback, unexpected feedback, gear machine control, CF axis control, parameter setting, or peripheral hardware, you can send us the CNC system model, alarm screen, machine type, axis information, program condition, and relevant parameter information. Our team will help check the possible cause.
FAQ About FANUC SV0413 Alarm
What is FANUC SV0413 alarm?
FANUC SV0413 alarm means axis LSI overflow. It occurs when the position deviation counter overflows and exceeds the register range.
What causes FANUC SV0413 axis LSI overflow alarm?
The alarm may be caused by opposite command and feedback directions, command output without actual feedback, feedback without command output, gear machine control conditions, CF axis control conditions, or unsuitable control/programming settings.
Why does the position deviation counter overflow?
In normal operation, the command value and feedback value are almost the same, so the error register value remains close to zero. If the command and feedback directions are opposite, or if only one side continues to change, the error register value keeps increasing until it exceeds the register range.
Is SV0413 common on gear machines?
Yes. SV0413 is commonly seen on gear machines because the command and feedback relationship may be affected by gear direction, spindle rotation direction, and special control conditions.
Can SV0413 occur on a vertical lathe CF axis?
Yes. SV0413 may occur on vertical lathes using CF axis control, especially when feedback exists without a corresponding command. In this situation, the control axis removal function may need to be used.
Which parameter bits may need to be checked for SV0413?
Depending on the machine condition, parameter bits such as 3706#6 and 3706#7 may need to be checked or switched when command and feedback directions are opposite.
Can M03 and M04 affect SV0413 alarm?
Yes. In some machine configurations, switching spindle rotation commands such as M03 and M04 may affect the command and feedback direction relationship.
Can G70.5 and G70.4 affect SV0413 alarm?
Yes. For some special control modes, switching between G70.5 and G70.4 may be related to the command and feedback relationship and may affect whether SV0413 occurs.
How can I fix FANUC SV0413 alarm?
Check whether command and feedback exist, confirm whether their directions are consistent, verify feedback distance, check gear machine or CF axis control conditions, review M03/M04 and G70.5/G70.4 usage, check parameter 3706#6 and 3706#7 if required, and use the control axis removal function when feedback exists without command in special control conditions.
Need Help with FANUC SV0413 Alarm?
If your CNC machine has a FANUC SV0413 axis LSI overflow alarm, please contact REACO CNC. We can help analyze the alarm cause and provide suitable FANUC CNC repair, command and feedback direction checking, gear machine troubleshooting, CF axis control support, parameter checking guidance, or related technical support.
Reference Source: Beijing FANUC. This article is based on technical documentation provided by Beijing FANUC. For More Fanuc CNC repair Cases and technical articles, please back to Fanuc Technical Support Center.
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