Ethercat do it this way, guess principle is very similar to using cascade coupled shift register. JTAG may also use daisy chain.
Have tried to use ordinary SPI in micro controllers in daisy chain but failed since there was an internal FIFO. It would be really nice if SPI and UART could be set up so data received on input is sent to output and DMA could transfer some part of the message to internal RAM or the opposite for values that should be sent. For this to work hardware CRC must also be avaible but then ordinary SPI or UART could be used daisy chained. Daisy chain with ordinay Micro controllers then message is queuqued internally add quite much delay. > Andy, thank you. > The page describes logic for a controller, and an evocation to use the boards > in a daisy chain mode. > Given a high level program, and the need, > this could be worked up to: > - a conveyor belt being notified of a new part placed at its entrance, > > * A robot gets notified the conveyor belt has a port for it to put into a > lathe / mill / treatment furnace, > * A lathe / mill / furnace tells the robot the part is to be inspected, > * An inspection machine tells the robot that the part is no / go and > is ready for packaging and exit conveyor / rework, > > as a work cell. > > Once again, thank you Andy. > > > James Isaac. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
