KB 0037
Read or Write reports 'Device error (CIP extended) 0x03010101: Connection failure: No buffer available'

CATEGORY

ASComm.NET

 

SYMPTOMS

Read or Write reports 'Device error (CIP extended) 0x03010101: Connection failure: No buffer available'

 

CAUSE

This error occurs when you are frequently closing and opening connections to the PLC.

TCP connections are not freed up immediately upon disconnect. They go into a TIME_WAIT state that can last several minutes.

If you are opening/closing connections at a rate that is faster than the TCP TIME_WAIT state, buffer resources will soon be exhausted.

 

SOLUTION

ASComm.NET manages connections for you.

Follow these guidelines to avoid buffer exhaustion:

• Never call Channel.Dispose or Device.Dispose during normal operation. Channel.Dispose should only be called when your app shuts down.
• Do not use one Channel for multiple Devices unless a gateway is in use. Instead, dedicate one Channel/Device pair to each physical device for non-gateway configurations
• Do not use a single Channel/Device pair to cycle between multiple devices. Instead, dedicate one Channel/Device pair to each physical device for non-gateway configurations