Constructing a look table with PLC5/40C

[stan 0]

I would like to construct a look up table for use to reference some densities against alloys. I have thought of several ways of achieving and I find I need to do a lot of coding to achieve. Does anyone know of a simple way of doing a lookup table in RSLogix5? Some examples would be appreciated!

[Ken Moore 23]

Well.... Your question doesn't give specifics, so I can't give a specific answer, but I would guess indirect addressing and an index pointer would be the way to go. Ken

[Chris Elston 79]

Indirect addressing is what you are looking to do. Take a look at this download http://forums.mrplc.com/index.php?act=Downl...ds&CODE=02&id=1 It's not RS5, but rather RS500 (Logix) hopefully you have the software or check out the pdf. Basically you create an INDEX that references the register number. N7:[X] where [X] becomes a wild card in indirect addressing.

[stan 0]

Thanks Chaku & Ken - I will go with indirect addressing. I had thought of using excel, but the risk of losing a pc is much too gr8 for that to be reliable.

[TConnolly 13]

Stan, Here is an example I cut from an old project and pasted into a blank project to give you a general idea. This was used for linearizing a value to an S-curve line that was divided into 20 segments and each segment was evaluated using the basic line equation Y=MX + B. Sorry, I cant post the whole project (proprietary tech issues), but this should give you an idea of what to do. lookup.RSP

[stan 0]

Thanks a lot...