CAN 8473 CCP DAQ Rate

[ARPL]

I'm using the NI-CAN USB 8473 to monitor an engine ECU.  I'm trying to set the sample rate for the measurement DAQ list.  The mc daq init.vi has an input labelled sample rate, but this is not exactly what I need.  It specifies how often the .vi returns data.  It does not seem to control how often the ECU transmits data on the datalink.  Is there a way to set the ECU's broadcast rate?  I need to slow it down to reduce the datalink's busload.  I tried using the vi's sample rate with various settings between 0 and 1000.  Nothing I did had any effect on the busload. 

[Gibson]

the Samplerate relates to the rate the CCP measurement data are "resampled" when they have been received to compare them e.g. with sampled DAQ data.

As you are looking to reduce the rate the data are transmitted there are typicaly 2 ways, but those need to be supported by the ECU.

1) check if there is another eventchannel available, which transmits the CCP data not as often

SampleRate specifies the timing to use for the samples of the (NI-CAN) task. The sample rate is specified in Hertz (samples per second). A sample rate of zero means to sample immediately. For a DAQMode of mcDAQModeDAQList, SampleRate of zero means that  MC DAQ Read.vi returns a single sample from the most recent messages received, and  greater than zero means that MC DAQ Read.vi returns samples timed at the specified rate. For DAQMode of mcDAQModePolling, SampleRate is ignored.

2) check if the prescalar is support by the ECU which relates to a specific Event Channel. To allow a reduction of the desired
transmission rate, a prescaler may be applied to the event channel. The prescaler value factor must be greater than or equal to 1 and can be set using
MC Set Property.vi using the DAQ Prescaler property.