How to convert from Alley B to Step 7

I am just beginning to learn PLC i have this ladder
http://imageshack.us/f/233/ladderw.jpg/

i take me about 30sek to write it down and it worked, i just wonder how to do the same thing in Step 7 (easy mode PLZ)

i read the manual that u have to create OB1 then FB1 and

declare IN and OUT and STAT then DB1

then Vat the Symbols and Call From OB1.. then going in

Vat the u can change the value omg its just go on and go on,

Its ther a easier way to do it? change the Value of a Counter

There is of course, an easier way.
First of all you can put all your program into OB1 if you are just feeling your way around.
Break the program up into blocks if it is a large program, or as you get to know your way around the program.
You can declare a variable as DB***.DBW** an use it in that format

for example DB101.DBW2 in the following:

If you look at the comparator there are 2 data types used here.
MW100 would be the same as B3:100 at word level
DB101.DBW2 would be like using N7:101

A clearer view, hopefully.

google08 said:

I am just beginning to learn PLC i have this ladder
http://imageshack.us/f/233/ladderw.jpg/

i take me about 30sek to write it down and it worked, i just wonder how to do the same thing in Step 7 (easy mode PLZ)

i read the manual that u have to create OB1 then FB1 and

declare IN and OUT and STAT then DB1

Click to expand...

OB1 is the central block calling distribution block, similar to the Main Routine in AB ControlLogix, where you call the main program.

You can create a FB or a FC for the logic, an FC does not require an instance DB. FB's require instance DB's because they use the DB as local memory (saves on using M flags).

google08 said:

then Vat the Symbols and Call From OB1.. then going in

Vat the u can change the value omg its just go on and go on,

Its ther a easier way to do it? change the Value of a Counter

Click to expand...

A VAT is a data monitoring screen, it is not a program. This is far superior than what AB has on offer. You can create many VAT tables and group together information you want to monitor or change and these can be saved for future use.



You example shows that on certain status you are changing the counter preset automatically, the VAT is a manual observation and change screen, your comparing different things here. You can do just as the AB and conditionally move new values ito the counter preset.

You can do a like for like copy paste in OB1.
The only exception would be that you'd need to use a Count Down counter.
(ofc you'd need to use S7 addressing)

Nothing there requires a FB, or a VAT, or symbols.

Thanks for helping me , i was silly tried to move in the CV

value which is the ACC value in AB side, that why its not works

and the PLC Sim crashed now i think its worked

http://imageshack.us/photo/my-images/64/problemsolve.jpg/

nice websites btw

www.liammoran.ie

u could become a teacher, we have some horrible teacher he dont

teach anything just give us problem to solve.