I've done some Shift Register in 400,200 and BRX Series Machines.. I'm needing some information..

1) Why are you digging into the Program.. I'm not thinking it's broken, you likely have a Sensor Problem..

2) For the Shift Register to work, Something has to 'Shift' the Bits.. Generally you have a Conveyor, or an Index Table that will move and the Shift Register is Indexed by an Encoder, or some Tack input..

3) For my Shift Registers, I always put 'Blanks' between the 'Data'.. Makes it easier to read the Data Stream.. If I have a Shift Register that is 8 Bits Long, it actually only holds 4 Bits of Data, with Blank Spaces ( Zeros) Located next to the Possible On Bits.. ( 1's ).. My Shift Registers are usually 40 to 200 Bits Long. So any tricks help.

4) Can you please Describe the 'Machine' and all the Sensors and what they do..

A Posting of the Program would be nice, So I can wrap my Brain around what is going on..

Cap

Cap is correct. The issue is likely not in your program if it has been working reliably for some time.

1) Check the sensor that is loading a "1" into the shift register. It is possible it is not turning off quick enough and loading a "1" in to registers for multiple items.

2) The divice that is shifting the register (Cap mentions a tach) is not pulsing consistently and shifting the register values as it should.

Thanks both of you for taking the time and sharing your ideas to help me to resolve the issue. So, appreciate it.

But the answer to your questions,

1- The system never worked properly. It has always been rejecting good and bad parts. This is why I think we need to make sure that if the original program has been written right.

2- But how the system works or supposed to work, I had attached the screenshots of the original program that shows sensors, shift register and the output Y70 that triggers the kicker.

Imagine a conveyor that running parts (piston pins) so rapidly. In one of the steps that is after final grinding, all pins have to be checked by rotary eddy current unit that is a third-party unit and sends the fault detect signal to PLC. X46 in the program that is used to change the data in the shift register. parts are going through the eddy current enclosure by forcing each other meaning that there is nothing to push them through or supply them to the enclosure then rotary eddy current rotates around of them while they are moving through for any flaws, crakes and the seam inspection. Then there is a photo sensor right after the eddy current enclosure X45 in the program that is used to reset bit C40 then there is a cylinder with a single solenoid that is always in reverse position by output Y70 in the program and will move forward to kick the bad part out once either bits C1001,C1002, C1003 or C1004 flicker or are activated (=1).

I am not sure if the right bits are selected when the bad parts reach to the kicker area? This is I am trying to make sure and find out what exact bit has to be selected.

I hope this helps and give you guys an idea of how the entire system has been designed here mechanically and electrically.

Let me know if you need more information. Thank you.

I'll ask again...

I'd like to see the ENTIRE program.. Screen Shots are a PITA to get a good feel for what is going on..

Thank you for the Information so far.. Especially the part about it never worked properly before..

I'm seeing an 'Issue'.. C40 is the Defect Detection input.. The One Shot from the Banner, tells the SR to Index.. However the Input ( C40 ) is immediately reset at the Following Line.. I'm 'Guessing' that C40 will be triggered back on by the Eddy Current Sensor on the Next Scan.. So why turn it off This time?.. I see no Trap to keep C40 Off until the Input from the Eddy-current Device actually drops..

A Bounce on the Banner input will re-trigger this SR.. Is there Some Input Limit to prevent that from Happening?..

I like to have a 'Clock' and Data input Enabled or Disabled by a few 'Devices'.. Like two Bottle Detectors, or the 'Bottle' can only be 'Seen' at a Particular Time or Position of Belt or Timing Screw, and the Belt or Screw is the 'Clock' Input..

It looks like this SR Set up is what I would cal.. 'Self Clocked'.. the Parts come in at Random Times, and the Fact that the Part is there, is what will allow the The Detection to happen.. and the Next part in, will shift the SR to it's next position.. but where is the Defective part now?.. Its ahead of the Present Part, but what allows you to know when the Part is in front of the Kicker?.. is it the 7th Part down the Line?

I like to make it that the Feeding Conveyor, Or the Discharge Conveyor, will actually have a Tack on it, and the SR will Shift ALWAYS when the Conveyor is moving.. as the Defective part is detected, it's Position 1 on the SR, and after '7' Pulses of the Conveyor Input, the Bad Part is at the Kicker Station..

Unless the Pins are in a 'Tube' or Tray.. then you can Self Clock, as the Pins are pushing each other down the Tube or Chute.. However, you have to have a separation of the Pins SOMEWHERE to get the Banner U Tube to Reset.. Like a 'Drop' of the Pin to the Conveyor will give you the Separation Needed?..

Cap