Serial communication (RS232) blocked after 25 hours fonctionning

[Montyto]

Hi everyone, 

i just finished my first testbench to burn 5 custom products simultany. i have to communicate with UUT every 2 min that my bench exchange 5 data frames ( Write 5 data & read 5 Data). 

after 25h11min of functioning, the testbench doesn't send any frame aymore. i remarked that the duration depends to number of UUT ( for example if test 4 UUT i have 41h52min and if i test 3 UUT i have 42h06min) i concluded that the maximum number of commands that the PC can send is 19226 commands. And now i don't know why is limited to this number of commands ? 

i notice that there is no execution error received, it just blocked! 

I use à LabView VI to communication with UUTs ! 

3 UUT ==> 42h06 // 1281 Lines/ UUT

4 UUT ==> 31h52 // 961 lines / UUT

5 UUT ==> 25.11 // 769 lines / UUT 

•  3845 lines are the total capacity of the PC that it can send 
• the total number of command is 
• 3845 * 5 + 1 = 19226

Any help or track that can oriente my investigations 

[crossrulz]

What are you using to communicate with your UUT?  USB-RS232 adapters can often have weird issues like this.  You should also check your USB power settings and make sure Windows cannot decide to turn off your hub to "save energy".

[Montyto]

Hi crossrulz, 

thank you for your response, 

i have an industrial PC that contains communication ports and i added 2 PCI Express UART Port 

3 UUTs are on PC communication port, 2 others are on PCI Express UART Port. 

I joined a data log exchanged between PC and one UUT during 32h2min before communication stops 

thank you for your support 

[Montyto]

about "save energy", i don't think, because the time that communication is stopped is not fixe, it depends to number of UUT: 

3 UUT ==> communication is stopped after 42h06

4 UUT ==> communication is stopped after 31h52

5 UUT ==> communication is stopped after 25.11 

[Minions]

How often are you communicating through each bus? 

It looks like it has something to do with the following: (#UUT * Stopped time) which would equate to around 126 hours. 

Are you saving this data to a file?  You might be running out of space.

This might also be influenced by:

• (Comm cycles per minute) 
• Length of characters saved