MATLAB: Might fopen fail on a tcpip object (127.0.0.1)

fopenInstrument Control Toolboxtcpip

t = tcpip('127.0.0.1', 9300); fopen(t); produced the error message

Unsuccessful open: Connection refused: connect

Best Answer

Several possibilities:

Your firewall / antivirus is blocking the connection
There is nothing listening on port 9300
the connection you're trying to establish is meant to be the server , in which case you need t = tcpip(tcpip('127.0.0.1', 9300, 'NetworkRole', 'server')
something else...

Related Solutions

MATLAB: Cannot communicate more than twice between server and client

tcpip() does the equivalent of bind() without SO_REUSEADDR https://stackoverflow.com/questions/14388706/socket-options-so-reuseaddr-and-so-reuseport-how-do-they-differ-do-they-mean-t

If you need multiple simultaneous connections, they will have to be on different ports.

One strategy in common use (by some of the key daemons, but not so much with user programs) is to publish a port for the client to make the connection to (e.g., the 30000), but instead of holding on to that port for the entire conversation, instead the server creates a new listener on another port, and responds to the client telling it what port the listener was created on, and then ends the connection. All of the clients need to talk to the same master port to get told what port the conversation will take place on, but those conversations are short and any refused connection can be retried a short time later to get the system a chance to finish the previous (short) conversation.

MATLAB: What is the throughput of the Instrument Control Toolbox 2.1 (R14SP1) with the TCP/IP protocol

Actual throughput can vary greatly, depending on the network. In real applications, it is most likely that the network is the limiting factor, not the Instrument Control Toolbox.

However, the TCP/IP connection in the Instrument Control Toolbox was designed for query-based communication with instruments, not for importing large amounts of streaming data. If you are importing large amounts of binary data, disable the terminator character in the TCPIP object prior to using the FOPEN function:

t = tcpip('127.0.0.1', 8012);
t.Terminator = '';
fopen(t);

Best Answer

Related Solutions

MATLAB: Cannot communicate more than twice between server and client

MATLAB: What is the throughput of the Instrument Control Toolbox 2.1 (R14SP1) with the TCP/IP protocol

Related Question