ND command for testing

Thanks. I’ll do this test. I keep you informed…

By the way, according my test, the only way for “instantaneous” reception is if I send the same API frame from the X-CTU soft (whatever the module I pluggued).
Is there any difference using the X-CTU “console” utility vs. Tera Term or another terminal emulator?

Thanks again.

Most of the other programs you are referring to do not have the ability to work with Hex data.