Author Topic: PMDX-424 driving Gecko G214  (Read 5269 times)

broered

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PMDX-424 driving Gecko G214
« on: December 12, 2016, 02:55:09 PM »
Does anyone have any experience driving the new Gecko G214 Stepper Motor Drivers with the PMDX-424 motion controller?

I currently have Gecko G203V's, which have a fixed native 10u-step resolution.  I can't get the minimum positioning resolution I need and Hardware reconfiguration isn't an option.
I'm considering the newer Gecko G214's because they have selectable resolution, as well as many other new features.

Comments?

Steve Stallings

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Re: PMDX-424 driving Gecko G214
« Reply #1 on: December 12, 2016, 05:58:27 PM »
You can run these drives by configuring the PMDX-424 to supply +5V on
its COM outputs of the motor connectors and wire the COM to the input
for +5V on the G214.

The G214 need access to both +5V and GND if you plan to use the ERR
(fault) and FS (full step) outputs. This can be accomplished by connecting
the GND of the G214 to the Lgnd on J12 of the PMDX-424. If you have an
older PMDX-424 this terminal may be labeled PCgnd.

Regarding resolution, you should keep in mind that micro-stepping does
not achieve full torque exactly at the desired location and you may have
trade offs between resolution and torque at rest. Extra microsteps can
help significantly with smoothness, but cannot magically produce extra
resolution that your motors lack the torque to support. If you are caught
between a rock and a hard place, there are stepper motors that use
400 full steps per revolution, which would double your resolution.
Steve Stallings
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broered

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Re: PMDX-424 driving Gecko G214
« Reply #2 on: December 15, 2016, 08:35:36 PM »
Thanks Steve!
(modified/simplified as I get things figured out)

I might have a problem supplying +5V to all 5 G214 drivers...  According to the G214 manual, each one requires 5V@15mA  (75mA total).  Based on the PMDX-424 information, it looks like I'm limited to 24mA.  If the PMDX-214 can't provide enough current can I use an external +5V PS? How would grounding be handled? 
« Last Edit: December 17, 2016, 11:36:08 AM by broered »

Bob at PMDX

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Re: PMDX-424 driving Gecko G214
« Reply #3 on: December 19, 2016, 02:12:15 AM »
The PMDX-424 can source or sink 24mA per output pin.  That means that each of the "COM" terminals on J7 through J11 can source or sink 24mA.
Engineering Hell: Everything's right and nothing works.
Bob's Corollary: If everything's right and nothing works, double check your assumptions.