Too Many Active Connections

What does 77 mean?

The drive has detected more than 5 active fieldbus or PC tool connections simultaneously. The system limits concurrent connections to a maximum of 5. Exceeding this limit can cause communication instability or prevent new connections.

• More than 5 simultaneous connections from PC tools (e.g., programming software, monitoring tools) to the drive's communication ports.
• Multiple fieldbus masters or controllers attempting to establish concurrent connections with a single drive.
• Network misconfiguration or a faulty fieldbus device causing persistent, phantom connections to remain active.
• A PC tool or fieldbus master connection was not properly terminated, leaving an active session open in the drive's memory.
• Drive firmware limitation or bug misinterpreting connection requests, leading to an inflated connection count.

Click steps to track your progress.

1. 1

   1. Identify and disconnect all non-essential PC tools (e.g., commissioning software, diagnostic tools) from the drive's communication ports.

2. 2

   2. Review the fieldbus network topology to ensure only one fieldbus master is configured to communicate with the drive.

3. 3

   3. Power cycle the drive and any connected fieldbus masters or HMI panels to clear all active communication sessions.

4. 4

   4. Use a network monitoring tool (if applicable) to identify the source of multiple connection attempts to the drive's IP address or node ID.

5. 5

   5. Verify the drive's communication parameters (e.g., P4-00 for fieldbus type, P4-99 for communication diagnostics) for any errors or abnormal settings.

6. 6

   6. Check if any remote access software or SCADA systems are maintaining persistent, unneeded connections to the drive.