Define the Three-Axis Motion Requirement
The machine uses three servos to position a robot-style arm carrying a spot-welding head. In teach mode, the operator manually moves all three axes to five target points and records each axis position. In automatic mode, the machine visits those five points in order, performs the weld operation, and returns through a defined zero point between targets.
Clarify whether the axes must follow a coordinated path or only reach each destination. If the three motion profiles are interdependent, use a multi-axis motion controller. Also distinguish the intermediate “zero point” from a machine reference or homing operation: store it as a normal waypoint unless the design actually requires re-establishing the axis reference after every weld.
Select the Motion Controller
For interdependent three-axis motion, the available evidence identifies the Delta DVP15MC and DVP50MC Motion PLC families as candidate controllers. Controller selection still requires confirmation that the chosen model supports the installed servo drives, required motion profile, point count, I/O for the welding cycle, and the intended communications architecture. CANopen Builder is the identified configuration environment.
| Decision | Required choice |
|---|---|
| Axis relationship | Determine whether all three axes require coordinated profiles or independent point-to-point moves. |
| Controller family | Evaluate DVP15MC or DVP50MC when coordinated motion is required. |
| Drive interface | Verify compatibility between the selected Motion PLC and all three servo drives. |
| Weld control | Reserve and verify the necessary command and completion signals for the spot-welding equipment. |
Store the Taught Positions
Create one position record for each taught target. Every record contains the commanded position for Axis 1, Axis 2, and Axis 3. Store the intermediate zero waypoint separately so the sequence can reuse it after every target. Define the position units and reference consistently; the source does not establish whether the recorded values are servo angles, encoder positions, or converted machine coordinates.
Determine whether taught data must survive a power cycle. If persistence is required, place the records in a controller-supported retained storage area and verify retention by cycling power; do not assume ordinary working memory is retained.
Program and Verify the Sequence
- Establish the axis reference and confirm the meaning of the stored zero waypoint.
- Enter teach mode, move the three servos to each target, and save all three position values as one record.
- On Start, command the first stored target and wait for confirmed motion completion before initiating the weld.
- After the weld completes, command the stored zero waypoint and wait for motion completion.
- Repeat the target, weld, and zero-waypoint sequence for the remaining four records.
- Run the complete sequence with welding inhibited, verify point order and clearance, then verify the welding handshake separately.
Do not advance the sequence using elapsed time alone. Each transition needs a confirmed condition from the relevant motion or welding operation. Add fault handling so an incomplete move or weld cycle prevents progression; the exact commands and status identifiers depend on the selected controller and drives and are not provided by the evidence.
FAQ
Which PLC should I use for three coordinated servo axes?
If the three axes have interdependent motion profiles, evaluate a Delta DVP15MC or DVP50MC Motion PLC. Confirm drive compatibility, motion requirements, and welding I/O before selecting the final model.
How do I save five servo positions in a Motion PLC?
Create five records, with each record holding the positions of Axis 1, Axis 2, and Axis 3. Store the zero waypoint separately and use retained storage only if the taught positions must survive a power cycle.
Should the robot home between every spot-weld point?
Not necessarily. If “zero” is only an intermediate safe pose, store and command it as a waypoint; use a true homing operation only when the machine must re-establish its position reference.