4220
Group not ready / group not ready for new task
Beckhoff · TwinCAT 2 NC
What does 4220 mean?
The NC group received a new motion task while it was still actively processing a previous task. This request is rejected to prevent interruption of the existing task and maintain motion integrity. Attempting to force a new task can lead to unpredictable motion, collisions, or data inconsistencies.
Additional Steps
Steps 1–2 are listed in Priority Fix.
- 3
Utilize command buffering mechanisms if sequential tasks are required, ensuring proper synchronization.
- 4
Check group status flags (e.g., 'Busy', 'Active') before sending new instructions.
Source: Beckhoff TwinCAT 2 NC
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