I have a palletizing cell. After each pallet is complete, the robot must wait for a staged pallet to get to it's final spot to put on a slip sheet. What I am wanting to do is perhaps put on a slip sheet while the pallet is in its staging area if there is a gap in production. I would want the robot to know it put a slip sheet on it when the pallet in front of it is done so it does not put 2 slip sheets on one pallet. Yes, I have flirted with putting a slip sheet on the staged pallet after the finished pallet is complete, but there is only about a 3 second window to do this, and I am afraid something may happen. The other day when I was doing this the robot put a slip sheet on the conveyor because the staged pallet never got there. How could i make this work?
Programming Question
- cat91345
- Thread is Unresolved
-
-
I'm assuming that you have a PLC and you are communicating for decisions before you move.
Unless you are controlling the whole cell with the robot (which we have no clue), all this action should be done with the PLC
The PLC will read the pallet is in place
The PLC will tell you to pick up a sheet
You will handshake with the PLC before you place the sheet on the pallet and after
-
Definitely need a lot more information.
How does the Robot know when the pallet is in position? It shouldn't even start to put on a slip till it knows there is a pallet there.
How would the Robot know when there is a gap in the line?
Personally I try to make programs easy for someone unfamiliar with the cell, or have only a basic lever of Robot knowledge to follow.
So instead of making a bunch of JMP LBLs, I'd make each pallet position it's own program, (as well as a Manual Function), then use an IF.....=.....Select instruction to decide which program to call. Don't forget to create zones and modify your DCS, especially if it's used in the original program.
Like Fabian mentioned, if it is using a PLC, those decisions really should be made by that controller.
Regardless, you can use flags to make that decision. That's assuming a lot, and if you want a more specific answer, we'll need more specific details, including the program if possible.
But assuming a lot, I'd just create a decision point before it goes to either position. Then use either the PLC remote controller, or Flags in a background program, to latch in a memory bit that is reset at cycle complete or whatever you find necessary.
That's what I'd probably do anyway, till the next issue arose anyway.
-
Definitely need a lot more information.
How does the Robot know when the pallet is in position? It shouldn't even start to put on a slip till it knows there is a pallet there.
How would the Robot know when there is a gap in the line?
Personally I try to make programs easy for someone unfamiliar with the cell, or have only a basic lever of Robot knowledge to follow.
So instead of making a bunch of JMP LBLs, I'd make each pallet position it's own program, (as well as a Manual Function), then use an IF.....=.....Select instruction to decide which program to call. Don't forget to create zones and modify your DCS, especially if it's used in the original program.
Like Fabian mentioned, if it is using a PLC, those decisions really should be made by that controller.
Regardless, you can use flags to make that decision. That's assuming a lot, and if you want a more specific answer, we'll need more specific details, including the program if possible.
But assuming a lot, I'd just create a decision point before it goes to either position. Then use either the PLC remote controller, or Flags in a background program, to latch in a memory bit that is reset at cycle complete or whatever you find necessary.
That's what I'd probably do anyway, till the next issue arose anyway.
Just like the pallet in front of it being built, the pallet has a sensor that will tell the robot that it is there. Right now there is a PLC sent UI that tells robot there is a pallet ready for a slip sheet. I would simply map another one saying pallet X is ready for a slip sheet also. I assume I would use a register and a counter to satisfy the second pallet getting a slip sheet.
-
Do you have access, knowledge on how to edit the PLC?
Is this the only job the Robot has? I've never seen a slip being put on a pallet before and am imagining the type of slip cover on a new TV.
Anyway, if you do have access to the PLC, the easiest way would probably be for it to make the decision of which pallet to put a slip on. There's a lot of ways to do it, but I would just duplicate the original program. Then modify it for the other station letting the PLC decide where to go. There's so many ways to do anything like this, but be sure the zones are set up correctly, especially if the work envelope changes. Depending on how close they are, I'd probably also move the Home or Pounce Pos between the two, but giving the lead pallet priority. Add some timers for each program and send to the PLC. Using that info, have the PLC tell the Robot to run the Staged program whenever there is available time, or with GAP MODE enabled. By gap do you mean that the exit conveying system will be detached from the main line, or do you mean the infeeding conveyor is gapped causing the robot to be idle waiting for production?
Main Program
.... = ..... Call Place Slip Main
.... = ..... Call Place Slip Staged
LBL 99
-
Do you have access, knowledge on how to edit the PLC?
Is this the only job the Robot has? I've never seen a slip being put on a pallet before and am imagining the type of slip cover on a new TV.
Anyway, if you do have access to the PLC, the easiest way would probably be for it to make the decision of which pallet to put a slip on. There's a lot of ways to do it, but I would just duplicate the original program. Then modify it for the other station letting the PLC decide where to go. There's so many ways to do anything like this, but be sure the zones are set up correctly, especially if the work envelope changes. Depending on how close they are, I'd probably also move the Home or Pounce Pos between the two, but giving the lead pallet priority. Add some timers for each program and send to the PLC. Using that info, have the PLC tell the Robot to run the Staged program whenever there is available time, or with GAP MODE enabled. By gap do you mean that the exit conveying system will be detached from the main line, or do you mean the infeeding conveyor is gapped causing the robot to be idle waiting for production?
Main Program
.... = ..... Call Place Slip Main
.... = ..... Call Place Slip Staged
LBL 99
Yes, I do have access to the PLC and can make edits. Referring to the gap, there is about 15 seconds where it takes the finished pallet to clear the sensor it's on, and tells the next pallet to proceed. That there lies the problem. I couild either add a slip sheet there, or add a program to do it when there is a gap in production (nothing to pick).
A slip sheet is nothing but a cardboard pallet cover that adds a barrier between the product and wooden skid.
-
If you are trying to do it at the pre-stage when production is slow during the pallet build, I would suggest the following:
- Have a signal telling you the pre-stage is in place.
- Set up a flag that says whether a sheet was placed on pre-stage or not.
- Monitor the Flag and the "In place sensor", if you have a gap and see a sheet is needed, then place the sheet
- Turn the Flag on after Placing the sheet
- Reset the flag whenever you lose the pre-stage pallet in place Sensor.
- Right before resetting, Set a separate Flag that says you have placed a sheet on your Build Pallet.
- Before beginning to build your new pallet, check the status of the second flag for whether you need a sheet or not and continue as necessary.
- Reset the second flag whenever you finish the Pallet you are building on.
If you are trying to place the Sheet during the transferring Gap Follow a similar setup to above with the first Flag, but don't let the prestage pallet advance before it gets a sheet.
Create an account or sign in to comment
You need to be a member in order to leave a comment