ovrTrans Queue

Hva betyr x240 ?

The transmit request memory has overflowed, indicating too many CAN objects are queued for transmission. This can lead to delays or loss of communication on the system bus.

• PLC program is attempting to send CAN messages at a rate exceeding the controller's transmit buffer capacity (e.g., `CAN_Send_PDO` called too frequently).
• A faulty CAN slave device on the bus (e.g., `Node_ID_5`) is not acknowledging messages, causing the master's transmit queue to back up.
• Insufficient CAN bus bandwidth for the number of messages and data volume being transmitted, leading to congestion.
• High-priority tasks generating frequent CAN transmit requests, saturating the queue and delaying lower-priority messages.
• Incorrect configuration of the CAN transmit buffer size (e.g., `CANCfg_TxBufferSize` parameter) in the controller, making it too small.

Klikk på steg for å spore fremgangen.

1. 1

   1. Review the PLC program logic to identify all CAN transmit commands (e.g., `CAN_Send_PDO`, `CAN_Transmit`) and reduce their frequency or data size if possible.

2. 2

   2. Monitor the CAN bus load using a CAN analyzer tool (e.g., Peak-CAN) connected to the bus to identify message bursts or excessively chatty nodes.

3. 3

   3. Verify the status and operation of all CAN slave devices on the bus (e.g., `Node_ID_5_Status`) to ensure they are online and acknowledging messages correctly.

4. 4

   4. Adjust the CAN bus baud rate (e.g., `CANCfg_BaudRate` parameter in `P8-01`) to a higher speed if the physical bus and devices support it, increasing bandwidth.

5. 5

   5. Increase the CAN transmit buffer size in the controller's configuration (e.g., `CANCfg_TxQueueDepth`) if hardware resources allow, providing more buffer capacity.