Query regarding common positive and common negative in a stepper driver

[arbj]

Hi,

I am connecting an Autonics make stepper driver type, MD5-ND14 to a Kinco PLC (K205 series) this has a sourcing output which cannot be changed to sinking.

I have tried out two different types of connections, common positive & common negative. The circuits are attached. Only the common negative works.

Could anyone explain why? I would prefer the common positive option. Any way this can be realized?


Link to MD5-ND14 datasheet
https://www.dropbox.com/s/6yvh4z2hsvnaedy/MD5-ND14.pdf?dl=0

Link to Kinco K2 datasheet
https://www.dropbox.com/s/381eokibm3ku39l/L011558 - Kinco K205E PLC Spec Sheet.pdf?dl=0

Thanks
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[kolyur]

As you pointed out, the K205 PLC has outputs that are sourcing only (common negative). Technically you might be able to drive one of the stepper signals by connecting the PLC negative to the stepper input, and the PLC output to IL+. In effect this would drive the entire 24v+ bus from a single PLC output, so you couldn't do both CW and CCW rotation.

If you want to have common positive to the stepper drive without changing the PLC, I think your best option would be to add a solid state relay in between. You would have to make sure that the switching rate of the relay is sufficient.

 

[arbj]

As you pointed out, the K205 PLC has outputs that are sourcing only (common negative). Technically you might be able to drive one of the stepper signals by connecting the PLC negative to the stepper input, and the PLC output to IL+. In effect this would drive the entire 24v+ bus from a single PLC output, so you couldn't do both CW and CCW rotation.

If you want to have common positive to the stepper drive without changing the PLC, I think your best option would be to add a solid state relay in between. You would have to make sure that the switching rate of the relay is sufficient.

Thanks....