Mitsubishi fx2n plc

I am looking for help, I am new with programing.
I am using a high speed counter on a a print press for registered printing, and speeding up and slowing down the mat. on a continuious run in order to pu the print where I need it to be.
but the counter is going over and under the preset count causeing
the print to land in differant place's. I believe it is because of the scan time.

Is this a new application? Or has this been working?

Have you made any changes to it?

I don’t know Mitsubishi’s very good, just learning, but I would doubt if it’s the scan time that is causing your issues

Can you post the program you may get a better response (PDF) if you can

is this a sheet feed or web ?

Have you checked the mechanical side of the encoder? Is it slipping?

Yes this is cont. web
the drum is a fixed speed mat speeds up to reach set dist.
then slows to match drum speed for print.
M8000-------------------------------C235 K9999 DRUM
M8000------------------DHSCS K3717 C235 M1000
NC/M8000-------DHSCR K3717 C235 C235


M1000------------------------------C236 K9999
RISING PULS
M1000-----------------DHSCS D136 C236 M2000
NC/M8000--------DHSCR D136 C236 C236

RISING PULSE
M2000-----------------------------RST C236


M2000-----------------------------RST M1000

Oh! Yes This Is New Aplacation

It Is An Old Print Press But Done A Refitt Took Out All The Macanical Timmers And Put In The Plc To Do A Registered Print
Whent From One Drive To 6 Drives Useing 2 Mitsu A700 Vfd's
And 2 A 500 Vfd's With A Didital Card To Talk To All Of Them