Note: Fanuc parameter numbering and names vary across control series (e.g., Series 0i/11/15/16/18/21/30i/31i/32i/Alpha i, etc.) and by software version. Parameter 1829 on one model may have a different function or not exist on another.
At its core, Parameter 1829 defines a search window. When a CNC program executes an M98 (subprogram call) or an M198 (subprogram call from an external I/O device like a memory card or DNC server), the control must locate that program number inside its memory. Parameter 1829 tells the control: “How many program numbers should I scan backward from the current point to find the target subprogram?”
Default value: 0 (or a small number like 10–50, depending on the control model and firmware).
Typical range: 0 to 9999. fanuc parameter 1829
If the value is set too low, the search fails, triggering an alarm (typically PS081 or PS082). If set too high, the search takes unnecessary time—especially in large, densely populated CNC memories.
| Property | Specification | |------------------|---------------------------------------| | Data Type | 4-byte integer (Real number, no decimal) | | Input Unit | Machine detection unit (mm, inch, degree) | | Sign | Positive only for positive stroke limit | | Default Value | Usually +99999999 (effectively disabled) | Note: Fanuc parameter numbering and names vary across
The most common symptom of Parameter 1829 being triggered is Servo Alarm 410.
✅ Heavy Cutting: For roughing in steel or Inconel, you might increase 1829 (e.g., from 150% to 200%) to allow the servo to push through heavy chiploads. ✅ Fragile Setups: For delicate parts or thin-wall machining, lower 1829 to act as a "torque limiter" and avoid crushing the workpiece. ✅ Troubleshooting: If you get random load alarms but the axis moves smoothly by hand, the value may be set too conservatively for your application. At its core, Parameter 1829 defines a search window
Parameter Number: 1829
Full Name: Servo Software Stroke Limit 2 (Positive Direction)
Control Type: FANUC Series 0i, 30i/31i/32i, 16i/18i/21i, and similar CNC models.
Parameter 1829 defines the second positive software overtravel limit for servo axes. It works in conjunction with Parameter 1828 (first positive limit) to provide a multi-stage safety boundary for axis movement.