Shift Register Applications.....

I am an electronic engineering student and would like to know some industrial applications in which shift registers are used. Any info/diagrams or links to other sites would be really helpful.

Hello xxx_750;

The last application I used shift registers was on a conveyor line, to keep track of the relative position of different packages on the line. This is a standard application by the way (look it up in the search feature of the forum, you should get a few hits).
In my particular case, we had 2 sugar bagging lines merging just before the packing machine, and we needed to be sure arriving bags would not fall on top of one another as this would jam the packing machine. We used 2 shift registers to simulate in memory the relative position and speed of the travelling bags on the 2 conveyors; optical sensors detected the bags and synchronized the shift registers. With this information, we were able to detect if there was enough space on the lower belt to recieve the higher belt's bag, and we could modulate a merging conveyor to place the incoming bag between 2 lower belt bags.
Hope this helps,
Daniel Chartier

Thanks, this is really helpful.

I sometimes use them in lift-and-carry or pick-and-place material handling in machinery. Products are "shifted" to each station.

bit shift

xxx_750 we use them to sort cants in a sawmill application. The last mill had 20 different sorts say 4" * 4" * 8' then 4" * 4" * 10' and so on. The shift register or bit shift is used to send this information down a 200 foot conveyor and lets them know where the bay is located where they are to be kicked off.
We also use a shift register along with a timer to keep motors from starting at the same time. We have motors from 450 hp to 150 hp that start and stop alot the shift register and timer make the logix simpler than using a bunch of timers because they motors also reverse alot.

:site:

I use them for loading generators. Also use reversible shift registers, with other functions, for load control. Read load getting too high, reverse shift register and drop load. Load goes low, increment shift register and increase load.

I am currently using shift registers on envelope folding machines, to monitor the progress of material through the machine and stop it if there is a JAM. Machine speeds are around 500 envelopes per minute.
Good luck. Tommy

I also use them, with random number generation into timers to drive the shift register and keep relays, to control solenoid valves for swimming pool water features. Bouncing jets, water waves etc. Took a fair bit of time to get it right. The random numbers had to be limited between certain points or the valves would not cause the water to bounce. Commonly known as "Jumping Jewels".

xxx_750,

It seems that tracking objects, packages, parts, bags is the most common use for shift registers. The last shift registers I used was for tracking boxes in a shipping warehouse. There was one main conveyor that fed boxes to 10 other branch conveyors. At the beginning of the main conveyor, there was an Encoder, a device that measures the travel of the conveyor. It was set so that every time the conveyor belt moved 1 inch, the encoder sent a pulse to the PLC. There was also a scanner that read a destination code from the boxes. I set up 10 Bit Shift Registers, to track boxes going to each of the 10 lines. Each line had a Diverter Gate that kicked the box off the main conveyor onto the branch conveyor. My PLC program watched the shift register for each diverter gate, and when a box accumulated travel inches equal to the distance from the encoder to the diverter gate (a fixed constant number that I measured with a 100-foot tape measure), I energized the gate for 2 seconds.

i use it in loading and unloading spark plug m/c. detect spark plug on rotary table for pressing washer, to unload them after washer inserted and pressed. ;-)

Shift registers

we use shift registers in our packing machines, there are several checks done during the packing process, some check for

improper folding,
some check for missing paper
some check for faulty product
some check for imcomplete product
some check for missing aluminum foil
etc

at the end of line, there is a ejector which seperates the good product from the the bad, based on the checks done,

I have seen some other packing machines with similar use of shift registers

SR's can also be used for product data files. Our application inducts conveyance IDs into a file using a Shift File Up the length of the file -1. The new data is then placed in the bottom position. When the file is later searched and the ID found, it is removed by a Shift File Down from the found position +1 to the found position with a length sufficient to get to the end of the file (Len - found posn.).

I use them in index tables and walking beam type machines to track product status or product assembly. I once wrote an article and did up an animated GIF you can look at here if you want.

Lancie:

I have an application just like yours that I am going to use an AB Micrologix 1500 PLC and an encoder. Do you have any sample AB code with the specifics???

Thanks,

Log to Board

Shift registers are used in machine centers in all sawmill automation. A log goes in one end and comes out the other as boards. The register has to track the log position in each section of the machine. The chipping heads and saws have to know when to move and its the shift register that provides the info to the PLC.