Indexed Adressing ?

[TOMC]

The System I am currently working on has a AB SLC 504. It also has a 4 station index dial. Each tooling nest has 2 sensors mounted in it they are addressed I:2/00 to I:2/07 (4 nests, 8 sensors). Nest 1 has I:2/00 and I:2/01 and the rest of the sensors go around the dial in order. My problem is, as the dial turns the sensors do to. I am tracking the nests as the dial indexes to let each station know which nest is there, to monitor the work being done. Indirect addressing works great for following the nests arround but how can I address the sensors along with them.

 

[glaverty]

I'm curious as to how you have these sensors wired. I would think that you would have a problem with wires getting tangled and the such if the sensors are rotating along with the table.

Why would you need to index address the sensors? If they are moving around with the nests you know that they are always pointing at the same nest. I could see it being confusing if they didn't move around with the nests because then you would need to know which nest the sensor is pointing at at any given time.

Maybe I am not understanding what you are saying though. Are the sensors always pointing to the same nest (which is what I think you are saying) or are you saying that the sensors point to a different nest every time it indexes. I guess some clarification is needed.

 

[TOMC]

FYI I am using a Balluff radial remote system to transfer power and signals to and from the sensors. No tangled wires.
This system welds projection nuts onto metal brackets. The sensors in the tooling confirm that the nuts have been placed in the tooling and are there through the whole process. I had to put the sensors on the dial because when the bracket is loaded (by an operator) it covers the nuts and they can no longer be seen. In the programming at each station I look to see which nest is there but I need a way to have the sensors address travel with the nest value.

I hope this makes sense. I have been working on this program for a while and made alot of changes I think I am getting tunel vision.

 

[glaverty]

Checked out the Balluf Remote system...pretty cool.

Ok so let me see if I understand your problem. Say for instance the welding occurs at station 4. Before you go to weld the nut to the bracket you want to ensure that the nut is there(Sensor 1) and the Bracket is there(Sensor 2). This is where (I think) your problem comes in, you don't know which of the sensors (I:2/00 - I:2/07) to check because it could be any one of the four nests?

Let me know if I am right or wrong on this. If I am not right please try to explain why you think you need to index the sensors as well.

 

[TOMC]

You got it.
Except (allways an except) both sensors look at nuts (the bracket is sensed by an outside sensor). Yes that is the problem which sensors do you look at at any given time. On top of that conditions change, preindex, postindex, end of cycle. I have the system running now but its alot of backwards code and crossed fingers. If a nut gets out of place for some reason or a sensor sees a nut thats not thier the whole thing goes in the dumper.
Its great to be me.

 

[glaverty]

Well I don't know a way to index the Inputs, I did have one quick idea that I thought of to at least tell you which sensors to use.

You would load the nest number into N7:0 and then depending on whether it is 1 through 4 you look at the appropriate sensors. You would have to do it for each nest or anytime you want to look at the sensors but it should tell you which ones to use.

Hope this helped.

 

[TOMC]

Thanks
That is more or less what I am doing now. The problem comes in when you are trying to get a more detailed idea of what is happening on the machine. If a nut was not placed (automatically) place another. Which one?
A weld faulted which nut?
The finished part was removed (automatically) but one nut stayed on the dial.
The code starts to go on and on and on........
If I could track the sensor positions with the tooling nests
indirect addressing?
indexed addressing?
my code would be potentially smaller and my head wouldn't hurt so much.

Maybe it can't be done the way I am doing it I don't know.

 

[glaverty]

It sounds like your making it more complicated than it is. Your saying you need to track the sensor locations with the nests. But the sensors are moving with the nests therefore if you need to check something in nest 1 it is always Sensor X and Sensor Y regardless of where the indexer is.

It almost seems like it should be easier this way because you don't have to worry about where the indexer is to check a nest you just look at the sensors that correspond to that nest.

I may be way off base here but hopefully the discussion sturred up something in your brain and gave you some ideas.

Sorry I couldn't help you out further.

 

[TOMC]

I score

You where right I was making it to complicated.

Address I:2/[N7:0]

Write the bit numbers for the appropriate sensors to the stations that are looking for them.
Thanks for helping me clear my head. I realy don't have anyone here who I can work this stuff out with. Everyone justs nods their heads and gives me a blank stare " very interesting let me know when you figure it out"

Thanks for your help.

 

[glaverty]

Re: I score

I realy don't have anyone here who I can work this stuff out with. Everyone justs nods their heads and gives me a blank stare " very interesting let me know when you figure it out"

I here you on that one. Just typing out the problems on here can help some times.

Good Luck.