I have an installed Flexpicker with a problem. The system is an IRC5 with IRB340. The picks are from a conveyor and the places are to 2 indexed work areas. (The place is actually an indexing conveyor, but I am only placing when the index is stopped.) When the indexing conveyor stops, the customer sends me a signal that I use for both index work area RobExe signals, giving me permission to execute on the targets. The customer then sends me one signal each for the two place positions. These signals go into the Position Available for each indexed work area. The customer turns off the position available signals first and then turns off the RobExe signal before the next index. Everything works great. However, if there is a missing cup in the place, the customer does NOT send the Pos Avail signal for that place cycle. It is possible for the robot to place in one position but not the other, or to place in both, or to not place in either.
The problem that I have is if there is only 1 missing cup, the robot still places into the position 50% of the time, even though the Pos Avail never got turned on for that cycle. If there is a string of 4 or 5 missing cups, the robot will always correctly not place in any of the empty positions.
I am not sure where to look for this problem. I know that the signals are correct from the customer. Any help is appreciated.
The Position Available signal is a digital output from the controller indicating that the robot has one or more place positions available on the indexed work area (i e this signal is set high after position generator has made a transition from low to high). Any signals used as digital input on the position available signal will be ignored by the system.
The “Position Generator” signal will create a new set of targets (either one originating from one predefined item or from all targets within a predefined containter).
Sorry about the mistake in my original post. I am bringing the customer output signals into the “Position Generator” input to generate the position in the two indexed work area queues.
The system works perfectly when I am filling the cups. When a cup is missing, there is about a 50% chance that I will still fill the missing cup, even though the customer signal for the Position Generator is missing. Further more, if there is a string of 4 or 5 or more missing cups, the system will correctly NOT fill the missing cups. I am trying to get the exact timing diagrams from the end customer as to when the three signals come on and off.
I believe your problem is most probably related to that the position generator signal has been pulsed too many times.
You can verify if the indexed work area queue is empty or not by entering a signal name into the “Queue Idle” field. If this signal is low when you expect the robot to stand still (position generator has not had any transition from low to high) this is most likely caused by the position generator having too many pulses received.
In order to verify this you may perform two different actions.
Crate a trap routine that is activated for each time the position generator has a transition from low to high. Verify that it has the correct number of pulses at all times.
Use the GetQueueLevel RAPID function to retrieve the current queue level for the indexed work area to verify that it is empty in-between each pulse to the position generator.
Thanks, I will look at these issues, especially creating a trap for counting.
Question: If I pulse the Position Generator X number of times, and then I drop the RobExe signal, shouldn’t all the positions in the Queue be dropped? I am having the customer use a chart recorder to give me the exact timing of the signals, but they should be as follows:
RobExe goes high; X ms later Position Generator goes high; X ms later Position Generator goes low; X ms later RobExe goes low.
If the Position Generator is “bouncing” and causing multiple positions, and the RobExe does not clear them out, then I could see this problem occurring.
The RobExe signal will only drop the positions generated from one low to high transition on the position generator signal, starting with the positions that were created by the earliest pulse. If multiple position generator pulses has occured the RobExe must set high and then low again to remove the positions created by the second position generator pulse and so on.