https://www.quora.com/What-does-state-mean-in-Representational-State-Transfer-REST

The fundamental explanation is:

No client session state on the server.

but this time we introduce builder.Services.AddSingleton<XObj>();

from my observation, I put activated the Init function after tearing cause the PICC time out occured afterwards. Tcl: //ERROR (code 5): PICC response timed out.

Tcl transmissions worked again after init protocols

err = TransmitTearing(txBuffer, out rxBuffer);
initResult = SendActivationHttpRequest().GetAwaiter().GetResult();