S7 instruction

[bdanelon]

I was wondering what i could do for a limit test like rockwell in the S7 world. I need to compare 2 Dints to another Dint

Thanks

 

[L D[AR2P#0.0]]

Either code FC3 as below and use FC3 when a limit is required, or use the logic from FC3 in your ladder as required:

 

[bdanelon]

thanks

 

[kamenges]

That won't perform exactly like a Rockwell LMT instruction. The LMT can be true inside a range or true outside a range. The inside a range case is like the S7 FC3, where the lower limit is less than the upper limit. With the LMT if the lower limit is greater than the upper limit you have the outside a range case.

Keith

 

[L D[AR2P#0.0]]

Keith is correct - I posted based on the following not realising there was another page