upgrading Machine PLC with no DATA

[DefenderY]

Hello,

I was given the task of removing an old PLC from a Muller Martini Bravo Stitcher from 1999. for this I decided to use a BRX PLC with 350 I/O. The data from the old PLC was no available since it was protected by factory, so I started from scratch. At this point I am almost over except for one thing, the bad copies ejector. BTW it is the first time I use Do-MORE Designer.

This is how it works:

When a copy is read by an input X0, it activates the stitching element, once the copy passes the stitching element the copy is read by another sensor X1.
X1 reads the metal staples placed in the copy. If a copy don't have the preselected staples in the paper, the ejector deactivates and that copy goes out, the it activates once again.

Between X0 and the ejector is 4 turns of the X0. All of this happens at any speed the machine is set .

Can anyone help me do a logical ladder for this ? My head is spinning at this point , any help is appreciated, thanks.

[Controls Guy]

Sounds like you need a shift register to remember the results from the last four parts to decide whether to eject or not.  Shift the register one position forward for each part.

[DefenderY]

Yes, but I cant find the SHIFT function, looks like I will have to do it with COPY

[Controls Guy]

There's FIFOLOAD and FIFOUNLOAD, but I'd probably just build my own from scratch too.

[BobO]

Yes, but I cant find the SHIFT function, looks like I will have to do it with COPY

SR