I made some small modifications to hostmot2 protocol. With this modification it could send 32 bit signed values in both values. It could also receive unsigned 16 number from an encoder and add it up into a 32 bit signed value. Temporaly behaviour is adjuster with stepgen step_type. To modify stepgen was the most suitable I found although to put it a category by itself may be a better idea or use a totally different protocol.
It is a useful modification if control loop is moved from linuxcnc to a lower level. If some delay i allowed and with control loop on lower level real time demands may be reduced and/or perfomance improved in som combination. It is possible to average jitter and have a receive FIFO which will both reduce jitter on actuated signal and reduce real time demand although actuation will be delayed by FIFO depth. Encoder style is useful for both ordinary servos and stepper generator. At least for stepper it might be userful with decimal point to place flanks within servo period to reduce jitter then stepper frequency is close to servo period. Are anyone else interested to get this into linuxcnc? Or know about a more suitable preferably standarized protocol? Regards Nicklas Karlsson ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
