Step 7 ladder logic help needed

Hey Guys I can’t seem to come up with the logic that I need on one of our operator stations
Any points in the right direction would be much appreciated First off I am working in ladder in Step 7 ver.5.5 sp3 but I could use stl. If need be, and have a CPU 319-3 PN/DP. I am needing to buffer a byte like a FIFO buffer. I have a Memory byte that is a 0, 1 or 2 depending on a recipe and while the operator is working on the part on the pallet that Byte is able to change if the next recipe comes in, so it will always go to a zero before changing again back to a 1 or 2 and the operator may still not be finished with the first part, so I am needing to buffer the change up to five times, in case the operator walks away from his station. The recipes will continue to come in, up to 5 before the line will stop. I have part present in station and part complete bits to use for triggers for next byte from buffer.

I don't have much time to reply right now but maybe one of these will help

https://support.industry.siemens.co...-pass-on-to-the-user-interface?dti=0&lc=en-WW

https://support.industry.siemens.co...-register-in-s7-300/28933/?page=0&pageSize=10

https://support.industry.siemens.com/cs/document/8685494/%22fifo%22-for-buffering-measured-values?dti=0&lc=en-WW


Is SCL an option?

Yes Scl is an option. I am not good at it but I can cut and paste very good.
yesterday I had found and looked at the same links you posted and worked with the first one on a simulator but could not get it working like I thought it should, and the second one the links in the article are broken.

Well thats no good.

Here is another link to a 'stacker' that someone wrote. If it is available maybe you could modify it to your needs.

https://support.industry.siemens.co...alue-into-datablock/28953/?page=0&pageSize=10

Thank you

Problem solved. I found and used FC85 FIFO and FC 84 ATT function.
and they worked fine again thank you for your replies.