In practice if you have ever had to set up a daisy chain topology network you will not like it. One problem is that one connector or device failure takes down the entire network. The new switch based Ethernet is much more reliable especially now with self test and green LED built into every end or every cable.
Talk about cables. I just got email from Leadshine and Stepper-on-line that they are promoting a new line of stepper motor with integrated driver. The driver is permanently fixed to the motor housing. This means two things (1) the driver is optimized for that exact motor and (2) there are no high current/voltage cables needed you run DC power and digital step/direction all the way to the motor. They also have new series of closed loop steppers but information and price was not available yet On Mon, Sep 4, 2017 at 8:56 AM, Nicklas Karlsson < [email protected]> wrote: > To daisy chain serial communication in a ring is well known old technology > which may have good real time performance. It is sometimes used for SPI and > JTAG devices. It is also used in the DMX protocol. Not the least it is used > on the new state of the of the art Ethercat protocol. Do anybody know about > a serial daisy chain protocol? > > I figured to send CANopen packages would work rather well but a standard > protocol is better. I have a choice to send exactly one message to each > node every time or allow to insert a few extra which may be used for > CANopen SDO messages but add complexity. Low overhead is good but if more > than half of bandwidth may be used for payload there is not to much to gain. > > Even though Ethercat is a good protocol I still think there is a place for > UART and SPI not the least for communication within circuit board and a > daisy protocol would work around the problem there is not enough available > ports available then only a fraction of the bandwidth is used. > > > Regards Nicklas Karlsson > > ------------------------------------------------------------ > ------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
