How to create and sort list in PLC?

I have a client with a panel view + that shows a list of items. Currently the PV+ uses the piloted list selector with 10 items. The customer now wants to aphabetically sort the list, only display items with entries, and expand the list size to 100 items.
I figure if I can sort the items that'll take care of not displaying the empty field becuse I'll adjust the visible length of the list. Problem is I'm a bit stuck on how to sort the items as I've never done this sort of thing in a PLC before. I was thinking along the lines of using the decimal value of the 1st char in the string and move the items into a temp array before moving sorted list back?
Any ideas?

What sort of logic controller are you using ?

I have some code for a simple alphabetical bubble sort around here somewhere, done in a MicroLogix 1400 controller.

The PLC is a ControlLogix L61 v 19, HMI is FTView ME v 6.00

I figure I only need to sort the list when the operator enters or deletes an item from the list on the HMI.

The ControlLogix ought to out-run the MicroLogix I used, and of course it's easier to manipulate strings in ControlLogix.

The attached ZIP file is an RSLogix 500 program in which I've stripped out all but the bubble sort.

N50:0-49 is an integer file with two ASCII characters in each element. These are the "color codes" you see mentioned in the comments.

N51:0-49 and N52:0-49 are integer files where each element contains a value related to the corresponding element in N50:0. These happen to be the power and speed of a laser etching system, so you'll see comments to that effect.

Convert this program to RSLogix 5000, or run it in an SLC (or Emulate 500, which I just did) and you'll see it bubble-sort the N50:0 alphabetical values, and move each related value to the appropriate location in the N51 and N52 tables.

Here is another version of a numerical bubble sort that will run on your ControlLogix PLC. I wrote it originally for a SLC 5/03, using Indirect Addressing. It also includes instructions and the math equations used, so that you can modifiy it as needed. To sort a character list, you would need logic to convert the first 2 or 3 characters to number values.

Thanks to previous posters I now have functionality to create and alphabetically sort a list of strings. Based on CLX emulator. I have sample PLC & HMI code if anyone wants.

Yes, this sorting question comes up here periodically. Please post your programs for future users. A PDF file-type print-out seems to be the best all-around method to allow the maximum number of people to read it.

Heres the PLC code for RSLogix5000, and HMI for FTView ME v 6

Code can be merged into 1 routine if you're only sorting one list. I am intending to eventually sort multiple lists, so have split functions into subroutines.

Here's a PDF of the PLC code

Thanks. Your method looks very efficient.