Hi PeLa,
The connection to the server remains after the first read. This can be checked using 'Nist_Time.Status' which returns the value ‘open’.
The issue of the second read returning an empty array is probably due to the reason that the server protocol is designed in such a way that it does not send additional data after the first message. The server keeping the TCP connection open might be an implementation detail or a timeout feature.
Since the server sends data once per connection, the most straightforward approach is to establish a new connection with the server every time data is to be read.
Here is a code snippet where the function ‘fetchNewTime()’ is called for each read:
time1 = fetchNewTime();
pause(5);
time2 = fetchNewTime();
function timeStr = fetchNewTime()
Nist_Time = tcpclient('time.nist.gov', 13);
pause(0.5);
tcpdata = read(Nist_Time);
if numel(tcpdata) >= 24
timeStr = char(tcpdata);
timeStr = timeStr(17:24);
disp(['Time now: ', timeStr])
else
disp('Not enough data received in the read attempt.')
end
end
NOTE: Add a pause after the call to ‘tcpclient’ as there may be delay in fetching the data from the server.
Hope it helps!
