external driver "iHSS60" connection-question

  • Hi,
    I want to connect an "iHSS60-36-30-31" (big 700mm axis) to the official "external expansion breakout board". In the datasheet from "Just Motion Control" they say the "iHSS60-36-30-31" takes 5V or 24V on those pins, so:

    • Is the "external expansion breakout board" working with 5V or 3V3? (I assume if with 3V3 I would give it also a try because it is more than 5/2...).
    • Can I connect the 6 pins directly to the other ones, means "S+/S-/D+/D-/E+/E-" to "PUL+/PUL-/DIR+/DIR-/ENA+/ENA-" becaus in the datasheet it tells me that either with commen cathode should use only the + signals and a common ground, and with commen anode should use only the - signals and a common VCC. Does wiring all + to + and all - to - do the same thing?

    EDIT: Just spotted on page 10 from JMC that "Differential signal" with "S+/S-/D+/D-/E+/E-" to "PUL+/PUL-/DIR+/DIR-/ENA+/ENA-" is also an option. So now it seems I just have to choose. Commen anode/commen cathode would be 2 less wires (ergo a thinner cable) but it seems I have to take either 5V or GND from one of the 2 "Heater"-outputs on the side... is this O.K.?


  • administrators

    You can either use the differential connection, or use a common 5V wire from one of the heater/servo connectors and just use the S-, D- and E- pins from the driver output connectors on the breakout board. Using a common 5V wire provides 5V drive. Using the differential signals provides a little less than 5V but it is still normally sufficient.

  • Thanks so much, opted for the differential-signal setup. Can you give me a last hint, how to setup microstepping:

    • duet is set for this axis to fullsteps -> external driver is set to *16 micro-steps
    • duet is set for this axis to *16 microsteps -> external driver is set to *16 micro-steps

    I think it is the first? Having the duet for this axis in x1 and having the external driver to the microstepping???

    Best regards, Lucas

  • administrators

    When using external drivers, the microstepping set on the Duet is ignored. So don't configure it with M350. Set whatever microstepping you want to use on your external drivers, and set the steps/mm in M92 to be correct for that microstepping.

    Don't forget to use the T parameter in your M569 commands for the external drivers, to extend the step pulse timing.


Looks like your connection to Duet3D was lost, please wait while we try to reconnect.