SCPI on a Linux Board - Part 3: TCP/IP Socket C++ programming

RE: SCPI on a Linux Board - Part 3: TCP/IP Socket C++ programming

Jan Cumps — Fri, 20 Jul 2018 18:31:23 GMT

I advanced on this design. The SCPI Parser and the Instrument can now both run and interact. Both act as a TCP/IP server.

When you send a SCPI command to the SCPI parser over the network, it interprets the command, and sends it over another port to the Instrument service. Then it sends any response back as a SCPI reply over the network.

It doesn't sound spectacular, but there are a few things that I wanted to try out and that work:

The SCPI parser is a C linux program that runs both as a TCP/IP socket server and client.

It's a server for SCPI commands, and a client that connects to the Instrument server to let that one physically execute the desired commands.

The Instrument is a C++ linux program that runs as a TCP/IP socket server and listens for actions. It acts on them and replies synchronously via the same socket.

This setup allows me to mix C and C++, split the SCPI part from the instrument API, allows for security needs on the SCPI arser only and allows the 2 programs to be executed as daemons - in a different security space than any other user.

RE: SCPI on a Linux Board - Part 3: TCP/IP Socket C++ programming

Jan Cumps — Sun, 24 Jun 2018 19:46:27 GMT

For a synchronuous interaction, this is the code:

[embed:dc8ab71f-3b98-42d9-b0f6-e21e02a0f8e2:3ef06e6b-9b7d-4651-b12d-db8be7f5e991:type=c_cpp&text=++++++std%3A%3Astring+x%3B%0A++++++acceptor.accept%28*stream.rdbuf%28%29%29%3B%0A++++++while+%28stream+%3E%3E+x%29+%7B%0A++++++++stream+%3C%3C+%22You+said%3A+%22+%3C%3C+x+%3C%3C+std%3A%3Aendl%3B%0A++++++%7D]

[View:/resized-image/__size/428x116/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-2c93c915-7a23-4dfa-bc7e-72189007d0ab/contentimage_5F00_206700.png:428:116]

There would be logic between the stream >> and stream << lines to deal with the incoming traffic and reply.

RE: SCPI on a Linux Board - Part 3: TCP/IP Socket C++ programming

DAB — Sun, 24 Jun 2018 17:31:36 GMT

Nice update.

DAB