How to use VISA with a telnet session

[RJM]

I have opened a handle to the TCPIP session and am able to send data via the interactive VISA program. My problem however is that I always get a message from the remote session indicating that it received in-band char of

It seems to me that the remote is really looking for VT100 sequences, which I tried to send via write (ie:\27[B) which is a down arrow. The remote session then complained about received 3 in-band chars - \27, [ and B?

Is there another means for me to escape the data?

rjmiller

[theW]

Hello,

I'm not sure I quite understand what you're trying to do. To me, "in-band characters" are the only things that really make sense over a TCP/IP connection--a socket is simply opened to a remote device and you send whatever data bytes are appropriate for the device over the connection. If you are literally trying to send 5 characters, "\,2,7,[, and B" and do not want the 27 interpretted as a hex code, then send this in VISA Interactive control: "\\27[B" and observe that the return count will be 5 rather than 3.

If I did not appropriately answer your question, please respond here.

Scott B.
National Instruments
Applications Engineering

[RJM]

Thanks for the input and I agree that in-band made sense. It turns out that the Tlenet Server which is an embedded "quicky" was waiting on the Telnet negotiation phase and any other character except the CMD code 0xFF(IAC) was being reported back in text as in-band character. the sequnce IAC, DO, ECHO (characters d255,d253,d1 - no spaces) pulled the unit out of negotiation phase. Most other Telnet server I have delt iwth simply time-out after the initial connection and use defaults - not this one!

rjmiller