Hardware-timed Analog I/O problems

[Andrew555]

Hi,

I'm using the bones of the "Analog IO Control Loop (hw timed)" VI which came with LabVIEW (attached file - runing Win95, LabView 6.0.2, NI-DAQ 6.9.1). Basically, I need to output in a timed fashion one point of an array of data following the acquisition of one data point using AI Single Scan.vi. I'm using the AO Single Update vi for the output. There are a number of difficulties, however:

1. At a certain point in the output array, I need to output another data point using a second AO Single Update call, which means that I must configure the AO Single Update vi for each outputted data point.

2. I use a trigger to initiate the AI Start vi. This is effectively a hardware trigger, although it is generated using code
in the same loop as the "Analog IO Control Loop", but outputted to another device and simultaneously inputted back into the DAQ board (PCI-MIO-16E-4). Therefore, as far as the Analop IO loop in concerned, the trigger is an external event.

I get an error "10609 AI Clock Configuration - a transfer is already in progress..." at random while running this Vi repeatedly, while after several hours of operation, I get "10444 AI Group Configuration - No more system memory is available on the heap, or no more memory is available on the device, or insufficient disk space is available". Any help or suggestions would be greatly appreciated.

Andrew.

[Bill B]

Andrew,

More than likely, you are getting the error "10609 AI Clock Configuration - a transfer is already in progress..." because you are already outputting a signal on the one of the analog ouputs. If you need to ouput two analog ouputs simultaneously, you need to use one of the functions that can handle multiple channels. The board is not designed to output two Analog Outputs independently because both channels share the same output clock.

The "10444 AI Group Configuration - No more system memory is available on the heap, or no more memory is available on the device, or insufficient disk space is available." Is most likely occurring because you are not reading enough data from the board and leaving scans on the onboard buffer. The scans build up over t
ime and the buffer overflows giving you this error.