I'm using the NI USB 6525 device to drive a DC motor. I've just used 2 digital outputs writing a bolean array to DAQ with 01, 10 or 00 if I want the motor to move left, right or to stop. The array written depends on a encoder reading. The encoder reading and the DAQ write are inside a while loop. The problem is that when I have a sudden transient of the encoder reading I get the error -201278 - Consecutive writes to a digital line occurred more frequently than the device can safely allow. But I'm sending 1 sample on demand and even if I put a 10 ms delay in the while loop (which gives a rate lower than safely allowed) I got the same message. Does anybody know about this?Regards

Digital I/O

NI USB 6525 Error -201278

Hi all,

Im running into some trouble with the switching rate for the usb 6525. I know the specs list it at 5 operations per second. Can anyone verify if this means 5 full cycles between on and off?Or does an operation simply mean a transition from 0 to 1 or vice versa? I was told that the usb 6525 can handle a switch rate of 5 Hz but I am only able to achieve up to 2.5 Hz before I get the error of "Consecutive writes to a digital line occurred more frequently than the device can safely allow." If anyone could clarify this for me, that would be awesome.

Thanks,

Tyler