6534: Error 4 when outputing data to DAQ using pattern_output_from_binary_file?

[jL637]

I am using the 6534 DAQ and is trying to output data from .txt files stored on my hard drive. The files consist of 8-bit characters that were originally stored via a modified version of the cont_pattern_input vi example.

When I output the data at slow speeds, I can see that the data is being outputted correctly because the data is a test data of pseudorandom bit sequence. However, I NEED the frequency to be at 16Mb/s, making it difficult to see if the data is outputting correctly or not. For a 117Mb file, the "update scans" stops at 112Mb, but the last bit when Error 4 occurs is always consistent.

Is there a way to check if ALL the data is properly outputted? And how do we stop the Err
or 4 which occurs when there aren't that many scans to read from the file? Thank you.

[RamziH]

Hi,

Error 4 is not related to the DIO card. Error 4 is an 'End of File' error; probably you are trying to read data past the end of file mark -- or output an amount of data that is greater than what you aleady have in the file. One way to test the signal is to use a binary file that divides the 16Mb/s by 16, for example, and check the output of one of the port lines and see if it has the expected frequency -- 1MHz in this case.

Regards,
Ramzi.