Shift Register in Omron PLC
In basic shift register is a register that is designed to allow the bits
of its contents to be moved to left or right.
Now when it come for a PLC to use such a register there are different
instructions which make use of this instruction according the
requirement.
Like in Omron PLC the SFT(010) instruction can be used to shift a bit.
The bit will shift from Right to Left.
When the execution condition on the shift input changes from OFF to ON, all the data from St to E is shifted to the left by one bit (from the rightmost bit to the leftmost bit), and the ON/OFF status of the data input is placed in the rightmost bit.
The bit data shifted out of the shift register is discarded.
When the reset input turns ON, all bits in the shift
register from the rightmost designated word (St) to the leftmost
designated word (E) will be reset (i.e., set to 0). The reset input
takes priority over other inputs.
St must be less than or equal to E, but even when St
is set to greater than E an error will not occur and one word of data in
St will be shifted.
When St and E are designated indirectly using index
registers and the actual addresses in I/O memory are not within memory
areas for data, an error will occur and the Error Flag will turn ON.
To learn how to implement the above instruction in PLC, follow the link
below, here you will find step by step method to use this instruction.
https://www.youtube.com/watch?v=aOjQnwl6mww
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ReplyDeleteThere are 2 conveyor system controlled by 2 motors. Conveyor 1 is for product
ReplyDeleteand conveyor 2 is designed for detection of empty box. When a start button is
pressed, box conveyor will move. Once a box has been detected (using a sensor),
the box conveyor will stop and the product conveyor will move and start to
count for 7 products (using a sensor). At the end of conveyor 2, there is a sensor
to detect the full box, so that the conveyor 2 will stop for 2 second and a solenoid
is used to push the full box into a trolley. The system will run continuously until
stop button is pressed......................................................how to solve the question using shift register ?