shift register

How long can use shift register on plc ? i want activated out put after 350 pulse from input. can help me on this topic

Depending upon the PLC type, simply cascade the output of one into the input of the other.

Or specify the "length" of one huge shift register. The PLC will assign the words as it assigns upwards.

Only limit is memory...

Surely you mean a counter 350 pulses then counter done bit operates output ????

I am new in Plc design system. Can you suggest which plc i should use for this operation.

chaudharijs said:

I am new in Plc design system. Can you suggest which plc i should use for this operation.

Click to expand...

With all due respect, this is like asking "What car should I drive?"

You need to supply AT THE VERY LEAST an I/O count (digital and analog plus voltages) along with a rough description of the process. Believe me, someone here will give you their suggestions.

I am working on conveyor system.

1. product loaded on conveyor plate.One pin is fix on each plate.
2. Detection PASS/ REJECT. (if reject detect pin is pressed)
3. Drying oven.

4. Pressed pin detected by limit switch after 350 product pass through conveyor and rejected product is removed.
5. good product is collected for packing.
6. pin reset.


This system is mechanical some times pin is not pressed fully. so it is not detected by limit switch and reject product mix it good.

Any one can suggest me can it possible to use plc by using shift register. which plc should i used for this system?

If you want to use 350 bits in a shift register, that is a pretty long shift register - 22 channels.

The only suggestion I can make is that the Omron CS/CJ series PLCs can handle this easily. At the 350th bit in the channels just use the 350th bit to reset the shift register.

You should take into account speed of the conveyor and lenght of the plate - this can help you to choose how powerful CPU you need.
As I'm a fan of Siemens S7 PLC - I'd say that the weakest S7-300 should handle that unless the speed of your line high (>20 pcs/sec).