enter code hereAn well-operating interface is made to the oscilloscope PM3384 via RS 232.

An attempt to realize this also for a PM3320A oscilloscope fails, because the command DeviceOpen["Serial" ....] does not make the signal DTR on the RS232 connector true (+10 V) as holds for e.g. Quick Basic. This means for this last oscilloscope that the interface is not ready. The only possible actions are putting the scope in ""Remote" and getting its identity.

An alternative way is to use an USB/IEEE488 interface, but this blocks in the same manner.

Question: How to set DTR on the RS232 port TRUE ?

Just as background, the code in its simplest form:

Clear["Global`*"];

baudratescope = 19200;

comportscope = "COM1";

(* definition data comunication expresions*)

CR = FromCharacterCode[13];

LF = FromCharacterCode[10];

ESC = FromCharacterCode[27];

(* interface to scope PM33xx*)

dev = DeviceOpen[
   "Serial", {comportscope, "BaudRate" -> baudratescope, 
    "DataBits" -> 8, "Handshake" -> None, "Parity" -> None, 
    "ReadBufferSize" -> 8192, "StopBits" -> 1}];

Print["Communication starting, Philips PM3320 connected?"]

FindDevices[""]

DeviceWrite[dev, StringJoin[ ESC, "8", CR, LF]];

DeviceWrite[dev, StringJoin[ "IDT ?", CR, LF]];

Print[DeviceReadBuffer[dev]];