Chapter: Zeroing
Overview
Zeroing establishes the reference home position for each axis. Incorrect zeroing causes move errors, positional drift, and repeatability failures. It is a fundamental daily procedure.
Why this matters for Target Tracking specifically: a rig's kinematics file (see Target Tracking chapter) defines the robot's geometry relative to its home position. If home is not zeroed accurately, the kinematics calculation itself shifts — a Target Tracking move built and shot correctly today will not reproduce the same camera/target relationship if shot again tomorrow, at a different venue, or after re-zeroing slightly differently, even though the job file is unchanged.
Key Concepts
| Term |
Definition |
| Zero Home |
Robot drives to the datum magnet, uses encoder ZM pulse to establish exact zero |
| Zero Direct |
Sets the current position as zero without moving — used to restore position after interruption |
| Datum magnet |
Physical magnet on rail that triggers the rough zero reference |
| ZM pulse |
Motor encoder's internal zero marker pulse — used for fine zero positioning |
| Zero offset |
cm value in Setups -> Axis Setup -> Track axis that shifts the zero reference from the datum magnet location |
Scope
- Zero Home procedure (track, arm)
- Zero Direct usage
- Datum magnet placement and ZM pulse warnings
- Zero offset configuration for track centering
- Re-zeroing after power loss or crash
- Zeroing after transport
- Absolute encoder systems (Staubli Bolt arm — no zeroing required)
Absolute vs Incremental Encoders
| Robot |
Encoder type |
Zero needed after power loss? |
| Bolt arm (Staubli) |
Absolute |
No |
| Bolt track (pinch wheel) |
Incremental |
Yes |
| Bolt X arm (Yaskawa) |
Requires pendant zero |
Yes — Bolt X QSG p.37 |
| Bolt Jr arm (Staubli) |
Absolute |
No |
| Jr+ arm (Mitsubishi) |
Absolute |
No |
Official Documentation References
Issue Index