The is a Spindle Switching Control Alarm (SPN1 7115). It typically occurs on machines equipped with a spindle switching function—such as those with high/low gear winding—when the system detects an inconsistency or failure during the switching process. Common Causes
Sudden power loss causes SRAM corruption. A line-interactive UPS for the control section (not the spindle drive) prevents write errors during brownouts. fanuc 7115 alarm