custom device FIFO questions

[MileP]

Question again about custom device.

If there are 200 output channels but every 100ms only 40 of them get updated by the driver.

Is it possible to write only those 40 channel data to the device output FIFO at a time?

What is the RT FIFO write speed when writing 200 channel data at a time?

Thanks.

[ThSa · Accepted solution]

If your custom device is an inline custom device you may update only dedicated channels per iteration.

In case of a asynchronous (parallel) custom device, you are forced to write always the entire stack of channels no matter what happend to the values. (if none of the values have changed, then it is ok to not call the FIFO Write function).

The FIFO Write doesn't cause a huge overhead.

You can easily benchmark that yourself though.

Tom