I'm afraid that the cheapest package of RSLogix500 is going to run you about $500 ... you can buy a copy from any Allen-Bradley distributor ... this one will let you program any of the SLC or MicroLogix processors ... but it will NOT let you do "online" editing ...
but since most MicroLogix processors won’t do online editing either, this software is a good fit for them ...
for online editing (with an SLC-5/03 or higher) you’ll need about $1,200 to get into the game ...
just be careful buying this stuff on e-bay ... some guys will sell illegal copies ... a few others will offer to sell you the “software” but no activation ... it won’t run without the activation ...
best advice: if you’re going to stay in this game, find some way to come up with the money and do it right ... are you just trying to learn? ... or do you have a paying customer? ... or are you trying to automate something for your own personal use? ...