Fanuc/PLC Question

I am also posting the question in the Robot Forum as well as my question relates to both a Fanuc Robot and an Allen Bradley PLC. So the basics first: I have a Fanuc Arc Mate 120iBe converted to Handling Tool with an R-30iA TP, and I am using it with an Allen Bradley 5370 L2 Controller.

In the PLC I am using the FSC Instruction to search through an Array of tags to find the next available spot in the Array that is not being used (it will have a value of Zero). As such the FSC Instruction will have the location listed in the Position of where the Zero value is located. The tag associated will be something like Tag[Control.POS], and this will contain the actual Position of the FSC Instruction.

My question is how can I use the Tag[Control.POS] as a tag that the Robot can use to place a part into that location defined by the FSC Instruction? The Value at the location is Zero, which will indicate that there is not a part at that location. Now I want the Robot to put a part at this empty location, and I don't know how to set it up for the Robot to understand that I want it to go to Tag[Control.POS]. Each time the transition from False to True occurs then the FSC does a new search, so then the Position will change once a part is placed at the location indicated by the Tag[Control.POS]. So I am only using one tag for Position, but the actual Position changes every transition of the FSC Instruction. Thanks!

I would make the tag(s) available to the robot via the fieldbus, mapping the inputs to group inputs on the robot side. Then, the robot program can use that information as needed. There will probably have to be some handshaking too for incrementing to the next position.

There will have to be some logic programming in both the robot and PLC; PLC using ladder and the robot using HandlingPro (tp files). Start with a blank piece of paper and work out the protocol with I/O assignments first, before coding on either side. Then document it in Excel to refer to because you'll need it.