software CAN check & CAN connection reset if needed?

Yao

Is is possible to perform a CAN connections check with the extensionboards on startup (in config?) and if one or more fails, reset CAN connections without resetting DUET?

oliof

@yao you can check the existence of a board in the object model (I don't currently run a CAN enabled setup, so I cannot look up the proper keys for you). The problem with resetting the CAN bus if nothing is connected is that it can't reliably work. You would need a way to cut the power to the board with a relay or something, but that would be a heavy handed solution.

Yao

@oliof Hi, thanks for the reply. The issue is that sometimes after a emergency stop (for whatever reason) the Duet and attached boards need to reset. However a leadshine attached to the 1XP boards remains powered and feeds a tiny voltage into the 1XP through the linked Dir wire.
This voltage seems to prevent a full CAN connect, sometimes.
The only way to solve it is to shut down all power and switch it back in in the correct order, DUET first, then leadshine.
I was hoping for a more gentle solution to reset CAN and check if all boards are present. If not Then reset only that sinlge board conection until it is connected again.

Yao

@oliof ah, but just to the one board that s not connecting properly? a relay would be a solution... as long as the main duet3 board does ot ned to shut down..

dc42

@yao said in software CAN check & CAN connection reset if needed?:

However a leadshine attached to the 1XP boards remains powered and feeds a tiny voltage into the 1XP through the linked Dir wire.

That doesn't sound right. Most external drivers have optically isolated inputs, so if they are connected correctly then they can't feed any current back to the circuit that is driving them.

Please provide a link to the datasheet for the leadshine driver, and a photo showing how you have connected it to the 1XD.

Yao

@dc42 ok, this is the setup. Proto picture with the leadshine powerd and the duet unpowered left. In the final setup this is no longer possible as the DUET always powers up about 12 sec before the leadshine receives its power.

http://leadshineusa.com/UploadFile/Down/MX4660d_V1.1.pdf

Page 9, par.8.2:
on 1XD the Step+ is linked to leadshine pin 2 (X axis step)
on 1XD the Dir+ is linked to leadshine pin 3 (x axis dir)

This follows trough for YZU axis

Then on the 4th (last in line) 1XD I had to connect a ground wire from leadshine (pin 21) to D0_step(-) for this system to work.
if I connected any other 1XD to a ground wire the rest after it would not work.

leadshine duet.jpg

As you can see in the left picture, after powering up leadshine, all 4 1XD board light up slightly.
They do not receive power from their own 24v source.
A bit unconvential maybe, but the source power for the 1XD array is OUT1 from main DUET3, If I find that any 1XD driver lost CAN connection (happens somtimes), I can reset the array with a trigger while leaving DUET and 3HC powered.

dc42

@yao thanks for the datasheet.

That 4-axis driver includes a "breakout board" which appears to be intended to interface to PLCs. The inputs to the breakout board are 12V sourcing PLC-style inputs intended to be driven by NPN PLC-style output, which explains why they feed power back into the EXP1LC. The datasheet mentions that the inputs are optically isolated, but unfortunately it also says that the ground connection to the breakout board is shared with the ground connection for motor power. This makes the optical isolation pointless, and means that ground noise caused by the motors will feed back into the 1LC.

So that controller is not suited for connecting to the EXP1LC. I suggest you use different drivers.

Yao

@dc42
I have been running this for a long time, once its up and running it seems to work fine.
Can it damage any components?
I am very happy with the leadshine performance...
What if I power the 1XD's direct from the leadshine?

Otherwise what driver would you recommend for the 1XD, Needs to be capable of DC-70v

Yao

@dc42 swapped for 4 of these https://www.damencnc.com/userdata/file/5205-1_EM882S_User_Manual_V1.pdf
Very smooth and fast movement but haven't seen if there is feedback. This system does not allow the drivers powered without the board also powered first.

dc42

@yao that looks like a more conventional driver with optically isolated inputs, of the sort that the 1XD was designed to drive.