Haven't done this before, I take it?
You need the following software packages from Rockwell: RSEmulate 500, RSLogix 500, RSLinx Professional (or better). First, fire up RSEmulate 500. Next, in RSLinx, configure a communications driver of the type "SLC 500 (DH485) Emulator driver". Choose a station number for the communications driver and remember what you picked (you can go back and look at it or change it later if you have to).
Now, in RSLogix 500, take your program that you've developed and do a full verification on it; fix any errors it reports. Then save it. Go back to RSEmulate 500. Open the program you just saved. It'll ask you for the station number; punch in any number other than the one you punched in for the driver in RSLinx. If you've got a debug file in your SLC program, be sure to punch in its number here too.
Now, jump back to RSLinx. Open the RSWho window, and look at the comm driver for the emulator you just set up. You should see your emulated SLC. Right-click on him and select "Configure DDE/OPC Topic". Give the topic a name and save it.
At this point, from RSLogix 500 you can go online to your emulated SLC, by browsing to it in the "Who Active Go Online" dialog. Note that you can't made edits to the program in the emulated SLC. You have to change your file offline in RSLogix 500, validate it, save it, and reload it in RSEmulate 500.
With that all done, set up your access name in InTouch to look at the application name "RSLinx" and the topic name of what you named your DDE/OPC topic in RSLinx.
And that should be it. InTouch will talk to your emulated SLC just as if it were the real thing.
