Instrument Control (GPIB, Serial, VISA, IVI)
buffering recieve data from serial port
1. No need for the outside loop.
2. You should not open and close the serial port constantly. Just open it once (which is done with the Configure Serial Port) before your loop and close it once after the loop.
3. Since you are dealing with binary (raw) data, you will want to make sure the termination character is turned off.
4. That FOR loop is useless. You can just wire the byte array straight to the chart.
5. Does the ARM constantly output the data once commanded or does it only output so many bytes after the command? If it is a continuous output, how does it know when to stop? You also would only need to send the request for data once. If it is on X bytes after the command, then use a constant to tell the VISA Read to read that number of bytes.
The following snippet is assuming you only send X bytes per read request.
@benyamin wrote:since im new to labview would you exatcly tell me what to do?
My snippet wasn't clear enough?
@benyamin wrote:data transfer speed is so high(like 1KHz) that can make problem?
At 9600 baud rate, you are bascially getting a byte every 1ms. That is an eternity to a computer. That is not your problem.
Perhaps you should share your ARM code so that we can understand the actual protocol you are using. We can give a lot better advice with that information.
Ok, so your ARM is just constantly sending data. No command is needed to start it up. This should be all you need to do.
And since you should be sending data at about 1kHz rate (1ms per data point), I would use something like 50 in the Bytes per read which would give you 50ms worth of data with every read.
