tracking a moment in time

[Noble 32]

Hello every body,

I have a issue and not quite sure how to go about it. First some background info, I work in a food processing plant chicken in perticular. What our goal is to be able to comdemn a perticular set of paws when the matching bird is condemned. The obvious soulution is using the bit shift function. What i want to know is is it possible to capture a moment in time say 20 secs (to make sure the paw is captured)using bit shifts.

Our current set up is using timers but we recently ran into an issue where after the the button is first pressed no matter how many other times it is activated it will only comdemn the first paw(activation)

All of his is set up on a SLC 504

 

[shooter]

a bit shift should happen when the chain is moved one hanger and not with time as this is dependent of the speed of the chain.

 

[Lancie1]

What i want to know is is it possible to capture a moment in time say 20 secs (to make sure the paw is captured)using bit shifts.

Yes, definitely - if your chicken conveyor has an encoder that tracks its movement. (For a slow-moving conveyor, some use a prox switch looking at a target on the conveyor head sprocket). Then as Shooter said, use a bit-shift register to track each chicken on the conveyor for whatever distance you need to track. Think "Position of Chicken", not "Time since Condemned".

Bit-shift registers are commonly used to track the position of many objects, and also to track relevent data about those objects. Each bit in a single shift register (you can use more than one shift register) can represent two states of a specific and idenfifiable object. Say you set up a shift register that shifts every time a chicken moves 1 inch (or 1 foot, whatever) on a conveyor. If a chicken is not "Condemned", the PLC sets its tracking bit = 1. If it is "Condemned", set its tracking bit to 0. Now when the feet are detached, move this same bit into a new tracking shift register, which will show, at any position of any set of feet, whether they are condemned, or not.

 

[bce123]

Talk about a speedy trial !!!!

 

[Lancie1]

Talk about a speedy trial !!!!

Chickens destined for the pot don't get a lot of ceremony or respect. In school I worked part-time on a egg farm. When some of the chickens were about 3 years old, we called the soup company to send out their flat-bed. We put the old chickens in coops with about 10 in each, and loaded them on the truck. I noticed that one old chciken had stuck her neck through the coop bars and got her head cut off when I slid the next coop beside the old one. I pointed out the headless chicken to the truck driver, and he said "Don't worry, it will make soup just the same".

 

[Noble 32]

The plant i work at processes about a half million birds a day. We have a solution to or paws problem but i wanted to look for other options then a metric butt ton of timers like we have now. We run 4 lines with 4 stations a peice for USDA. As of right now each station has 5 timers, so some quick maths brigs us to 80 timers. I know the bit shift would work if or picking lines(the line where the feathers ae knocked off) had the same amount of shackles because our other plants work that way. Being one of the oldest plants we have sped up our processing by adding more lines in but not equalizing the lines.

I was just curiousif there was some other way to program it instead of timers.

 

[Lancie1]

As of right now each station has 5 timers, so some quick maths brigs us to 80 timers.

Are these PLC logic timers? If so, you could probably replace the 5 station timers with one PLC timer, set for the longest time. Then use comparison instructions to take care of the first 4 times.

If your chickens are being moved by a chain, and that chain position is known or can be counted, then you could use a PLC Counter instruction instead of timers. But that may not gain you very much.