I switched the GET and USER1 because the Arduino should probably begin with the control directive I want the macros in PLX-DAQ to run (DATA, LABEL, CLEARDATA, RESETTIMER, SET, GET, etc.). Changed it also back, made no difference. There seems to be no serial available.
Also I checked the response for several seconds.
And I tried to check the arrival of the response with serial.available(). Nothing.
So I guess the statement Serial.println("USER1,GET");/Serial.println("GET,USER1"); isn't working or something with the serial connection at all.
But how to get the status then ?