clx summing question

[johnfarrugi]

I have an array of real numbers. The array dimension is 100. How can I get the sum of the entire array?
I am using RS5000 v17

 

[Ron Beaufort]

take a look at the FAL instruction ... you'll probably also need to use a CLR to "zero out" any previous sum just before you do the FAL ...

 

[CroCop]

Write a ST routine that goes:

i := 0;
Total := 0;

While i < 100 Do
Total := Total + Array
i := i + 1;
End_While

 

[robertmee]

Not everyone has ST licensed CLX, otherwise a good suggestion.

In Ladder, you could also use the Average instruction (AVE) and multiply by 100.

 

[johnfarrugi]

the FAL option worked great...Thanks

 

[CroCop]

Not everyone has ST licensed CLX, otherwise a good suggestion.

In Ladder, you could also use the Average instruction (AVE) and multiply by 100.

Absolutely true, but I can't imagine programming in 5000 without it........

 

[TConnolly]

Absolutely true, but I can't imagine programming in 5000 without it........

+1

 

[robertmee]

Absolutely true, but I can't imagine programming in 5000 without it........

I'm with you there. I was dismayed when CLX first came out without STX at all after having it available in PLC5 for so many years. BUT, in that it costs more as an option, there are many plants that are doing SLC or PLC5 to CLX conversions that don't purchase it.

 

[daba]

In Ladder, you could also use the Average instruction (AVE) and multiply by 100.

I like that - so obvious, now why didn't i think of it ....

my solution would have been to use either a FAL (clunky with it's indexing), or a FOR loop (slow).

 

[johnfarrugi]

I like that - so obvious, now why didn't i think of it ....

my solution would have been to use either a FAL (clunky with it's indexing), or a FOR loop (slow).

The AVE instruction will not work in my situation because I want to get the exact sum of the array and not the average.

 

[robertmee]

The AVE instruction will not work in my situation because I want to get the exact sum of the array and not the average.

That's why you multiply it by the number of your array. If you have a 100 numbers, take the average and multiply by 100 then you get the sum.