ERR_PACKET_ALLOC
Firmware use only
Allen-Bradley · MicroLogix 1400 Programmable Controllers
What does ERR_PACKET_ALLOC mean?
This error is for firmware internal use only, indicating a failure to allocate a packet. This suggests a memory issue within the controller for Modbus TCP packet handling, preventing new packets from being processed or transmitted.
Common Causes
- Insufficient free memory for Modbus TCP packet structures.
- High volume of network traffic requiring more packet allocation than available.
- Memory fragmentation within the controller.
Repair Steps & Checklist
Click steps to track your progress.
- 1
Reduce network traffic volume directed at the controller's Modbus TCP interface.
- 2
Review controller memory usage and optimize other applications if possible.
- 3
Restart the controller to clear temporary memory issues and free packet resources.
Verified technical data. Last updated: March 2026
Related Faults
Source: Allen-Bradley MicroLogix 1400 Programmable Controllers