FB and DB's link together SIEMENS 315-2 PN/DP

Hello!

I'm new in PLC programming I have a PLC 315-2 PN/DP from Siemens, I want to store the status of one input (or more) in a DB for every cycle 0 to 1 of the input (boolean representation) and after that i retrive every result and make the next decision. It's like a Fifo buffer for storing multiple variable changes, how could i do this?

Thank you!

You want to remember the last 5 states?

cjd1965 said:

You want to remember the last 5 states?

Click to expand...

Yes.

Im curious why you want want to do this. Do the states enter a table at the top then fall out at the bottom? Do you want to capture in groups of 5? Is it changes of state of time period, say every second or whatever

cjd1965 said:

Im curious why you want want to do this. Do the states enter a table at the top then fall out at the bottom? Do you want to capture in groups of 5? Is it changes of state of time period, say every second or whatever

Click to expand...

Thank you for the reply,

I have a program for sorting boxes using two sensors I0.0 and I0.1 they represent lower and higher box. I wrote a program in plc that sort one box at a time using those sensors, now i want to use a buffer (FIFO i guess) that stores multiple values of inputs I0.0 and I0.1 in a DB for multiple boxes not one at a time. I don't use a tabel right now, the time and groups doesen't matter just to store variable and extract it.

You can use FC85 in Libraries - Standard Library - TI-S7 Converting Blocks

This is a FIFO and the help file (click the block and press 'F1') is quite good for explaining its use.

;-)

Thank you i will take a look.