Bottle Rejection based on the sensor

Sanz2022

Hi,

I need to make some logic to reject damaged/cap missing bottle. Is it possible to use BSL instruction to implement this? or any other method? I searched for sample application but could not find any yet

Regards

Sandy

 BSL? As in the "bit shift left" instruction found in MicroLogics et.al.? Do you have a Rockwell processor or a Siemens one?

You are right that shift register can be used to solve such an application problem. The most basic shift registers in the S7-1200 can handle 32 bits. Cascading is also possible. 

The recommended solution would be to use a bit array in a ring buffer configuration. There are some articles written about a "ring buffer" within the forum if you care to use the forum search.

The alternative to this is to use an array and track time-stamps. This can be very handy if the count of items being tracked is few but the tracking distance is very long.

The right fit for your application would depend on the details of the application. Things like..

1. Tracking distance
   
   
2. Items being tracked
   
   
3. Time between items
   
   
4. Time between indexing the shift register
   
   
5. What is used to track movement: time or encoder
   
   
6. Choice of hardware
   
   
7. Choice of coding language
   
   
8. Have you done a similar application elsewhere?

So.. what are your thoughts?

EDIT:
An application that used shifting of bits in an array has been discussed here [LINK]. In your case the moving objects will not be blocked.

You can probably find a suitable set of FBs that help manage rejects from point of reject detection until product is rejected from the main production line or area.

I've used a "registration" timer where the preset is based on current product speed and is based on how long it takes for product to move from detection zone to rejection zone, and then when the timer times out, it triggers a rejection action.

The reason it's FBs is it needs memory, and there should be a multi-instance FB or an array of FB calls where each rejected part gets a unique FB instance so it can independently track that single part.

You also need logic to handle situations where the production line STOPS after reject product is detected but not yet rejected.  What do you do after the production line restarts?  Automatically reject, or do you require manual intervention? If so, how do you visualize the location of all the rejects currently not rejected?

It's the edge case handling that makes all the difference between useful and robust reject handling - and follow-up business by customers...

If your production line has position information, you can use that to track product as well, and it's typically more accurate than timer-based rejection, especially when the production line rate can vary dynamically.

Sanz2022

Hi,

I need to make some logic to reject damaged/cap missing bottle. Is it possible to use BSL instruction to implement this? or any other method? I searched for sample application but could not find any yet

Regards

Sandy

jacek d

You may also hit it big.

@jacek: Perhaps that is shooting a fly with a shotgun.
So which building blocks of the library would you use for this task?

qwazee

@jacek: Perhaps that is shooting a fly with a shotgun.

So which building blocks of the library would you use for this task?

So I stated it - you may hit it big. As from this vague description it's hard to understand what the task actually is. Is it upgrade of existing project ? Or maybe a new one ? Or maybe translation from one PLC manufacturer to other one ? Is it whole functionality ever needed ? There are many other question to decide to go for this ready-made solution or not.

My knowledge of this library is limited to its purpose. I've never dived in the implementation details as we have our own building blocks for this task.