In my project, I’m using a line with two infeeders and two outfeeders. The projects are as follows:
Infeeder1 to Outfeeder1, Infeeder2 to Outfeeder2
Infeeder1 to Outfeeder1, if Outfeeder1 not available, Infeeder1 to Outfeeder2 (Outfeeder1 has priority)
Infeeder2 to Outfeeder2, if Outfeeder2 not available, Infeeder2 to Outfeeder1 (Outfeeder2 has priority)
The problems comes when we are running program 2 and 3. What we require is for the robot to pick the products from a single Infeeder, place it on a single Outfeeder and complete the pattern before it can continue on a second Outfeeder if the first outfeeder is not available.
What we saw during simulation is that the robot will take the product during from the Infeeder and place it on the first Outfeeder to be available. If the second Outfeeder available signal is given during the process, the robot will place the product alternatively on both Outfeeders, breaking the palletizing pattern.
Is there a way to set the robot to complete a pattern before it starts placing on the second outfeeder?
Already tried that, but what would happen is that if the second pallet is triggered as well, the robot will wait for the product for the second pallet to appear before it would continue for the first pallet.
This would defeat the purpose of it clearing off one pattern before it continue on to the next pallet. And as such we resolve this issue by not setting the pallet trigger signal for the second pallet as it would cause this issue.
The current issue with this is that both purging and completion of pallet triggers the pallet complete signal. Due to site conditions, we would require the robot to purge a pallet initially in order to ensure the safety of operation. This would in turn trigger the pallet clear signal.
But what happens is that we did a cross connection of that signal together with a signal to indicate the robot is at home position, so that the robot will allow the system to clear the pallet it is working on before it continues to work.
If we do not trigger the pallet trigger signal, the complete signal will remain on, and as such, the signal for clear the pallet will repeat for as much as the times the robot returns to home position. Is there anyway around this?
Hi Thomas,
a general idea: you can use “stop flow” to temporary stop the palletising on one outfeeder. Restart the flow when you want to continue palletising. Meanwhile, the robot can work on the other outfeeder e.g. until the pallet has been completed. The tricky thing is to decide when to stop the flow and with what stop option to specify, e.g. “after cycle” or “immediately”. Using stop option “immediately” may block the other outfeeder as well if it is ordered at the wrong moment. “After cycle” is safe but will require one extra pick/place cycle. Stopping the flow before generating the next pallet is a fast and safe alternative.
By using the infeeders as masters and declaring two different operation sets on each infeeder, the PLC will, by triggering the right operation set, be able to decide where the products shall be placed.
To interrupt and purge a half made pallet, you just lower the RobotExecution for the outfeeder after a cycle is finished. The Operation Set Complete signal for the outfeeder will then raise. To continue to palletize to the other outfeeder, you change product I/O value and trigger the infeeder.