rslogix5000 compare values and use

I am using rslogix5000 and a controllogix L73 Processor. I need to compare 4 analog position inputs and use the highest or lowest input value to move into a set point to start the next move command. So if position 3 input is the highest out of 1,2,3 and 4 I want to move position 3 into my set point for the next cycle. Does anyone know of an easy way of doing this instead of making a lot of GRT or LES to compare all of the positions to pick the on I want? Thank you

Welcome to the forum.

Copy to an array. Sort the array. Then take the lowest and highest from each end of the array.




However, a sort requires the processor to make a lot of comparisons and move a lot of information around, it probably takes longer to execute than just using three LES and three GRT compares.

Thank you very much TConnolly I will try them out and see which one works the best for me.

TConnolly, I tried the SRT instruction and not sure why it is not sorting in the Ascending order like the instruction is suppose to. Any ideas on what I did wrong? here is a pic of what I have.

I *think* the SRT puts the Highest Value in SortArray[0] and then lower values from there.

After sorting, look at your SortArray[] and I bet you will find they are highest to lowest.

If that is in fact the case, then just move SortArray[0] into position HIGH and SortArray[3] into the LOW position.

Thank both of you for your help. After playing with it I had to turn off the Sort_Pos to hold the positions in the Array. Then I had to execute the SRT command and it then sorted the positions that were moved into the Array.