Digital I/O Slow Response. But, everything fine after reset from MAX

[JongTheng]

Hi,

    My system is, CVI8.1, NIDAQmx 8.5.

    In a PXI system, i having 8 PXI-6527 IO cards, every port of the line created one task when the program initiliaze.

    the problem that i facing is, the I/O response is slow after some times. the recover matter is stop my program, RUN MAX and reset all the devices one by one. by the way, in CVI there is a function name DAQmxResetDevice, i reset the device in the program start. but it's seem like not function.

    is there anything that i miss up. pleae advice. thank you.

J.T

[Paul_C.]

Hi J.T.,

The DAQmxResetDevice is the correct function call.  The function returns the device to an initialized state. Calling this function is the same as doing a reset on a device from MAX.  The DAQmx Reset Device function immediately aborts all running tasks associated with the device. This action stops and releases any resources reserved for a task, such as trigger routes.

The reset device also performs a few actions to digital I/O lines.  It sets all digital I/O lines to the configured power-up state (which can be set programmatically or in MAX on the 6527). You might take a look at setting the power-up state here.  It also tristates all digital I/O lines and returns digital output-only lines on devices that do not support configurable power-up states.

Are you using clocked DIO or software timed?  Have you tried watching your memory usage while the program is running?  If you see your available memory steadily drop, this may indicate that your having some type of memory leak in your program.  Take a look here at an article about how you can get a memory leak when you don't use the DAQmx clear task function.  Also, take a look at the additional links they may be helpful too. 


I hope this helps,
Paul C.