steps to designing a PLC program

[david90]

what are YOUR steps/stages to designing a PLC a program? This is not a homework question because I'm not even in school. I'm just learning on my own and I would like to know how other people do things.

For me, it's

1. Defining machine logic
2. Drafting hardware schematic
3. Express logic with truth table
4. write boolean expression
5. Implement boolean expression with ladder logic instructions
6. testing and debug.
7. done.

I have used the steps in the past with success.

 

[Lancie1]

You have a nice complete list. I usually skip most of those, but the one that you probably skip should be #1 on everybody's list.

1. Talk with customer about what is needed. Talk with customer again and again.

2. Write a description of how the program will work, changing it as customer figures out what s/he really needs.

3. Write rung comments for each output.

4. Write the rest of the program.