low update rate with ftdi

[flori2]

Hi, recently my company changed I/O communication of a custom ADC board from RS232 to usb using FTDI245R chip. Using ftd2xx.dll I obtain lower update rate of the measurements ~60-100ms instead of 20ms (rs232). Anyone noticed something like this, how did you fix it? I just used the drivers provided by FTDI: open device (once), reset device (once), flush TX, write bytes, queu status, read bytes.

Thank you

[muks]

U r right.IT is really frustrating.I found out the hard way.Finally when i used BCP for serial communication the updation was much faster and i was able to curtail the data loss.Using the d2xx function.Initialize purge and do everything once and i mean it only once.Put the read buffer in a while loop and dont give the number of bytes to read from the output of transmitt buffer as suggested.Instead define your own number of nits to read.obviuosly the buffer status will be checked once and then the while loop will start executing and ur updation will be fast.I am doing the samething.

[flori2]

Hi, I had problems with my PC. First I had to format it because on other computers the applicationd was not so slow. Second I was using LV 8.5 and I figured out that LV 8.5 is really heavy for my application (I use plenty of indicators) had 45% cpu usage on a Intel core duo (2cpus). Then I switched back to LV8.2 (no problem with LV 8.2) and my application really improved a lot using FTDI compared to rs232.

Anyway I had to purge the buffer outside the sequence of the example FTDI provide. I purge the buffer in sections when I do not use the device.

[Julio_HDT]

hi, im using ft245 too, i took the tfdi's example, but i cant to do communication very well, could you post you example

thanks

JC UASLP, MX