Find unused addresses in Siemens/TI APT

My question:
How can I see a list of PLC addresses (such as %V1012) that are available but un-used in the processor?

Background:
My client has asked me to do some "quick" maintenance of an APT v1.9 program for a TI 555 processor. Not much time in the budget for formal training. I can do most of what's needed using the existing program for examples. I'm simply adding more-of-the-same items, including items with addresses that can be "seen" by the two different HMI packages - hence my question.

I'm betting there is a way, but I have not yet found it in the REPORT or CROSS REFERENDE tools.

Thanks for your help...
VJG

Not familiar with APT software, but I am familiar with the 555 plc. If APT is like Ti-soft, then the only thing you can see is what has been used, never what is free. This is because of the way the TI memory works. You have a predefined amount of variable memory for usage, 2k, 16k, whatever, you can call it anything you want.

So if you've used V1 to v9,000; which V's are available, all off them except the ones already used, you can call the next V, V10,000 if you like. I have some older programs that a LOT of people have muddled with over the years, the original program used V1 to V5000, the next guy used V6000 to V7000. Then the next guy jumped all the way to V20,000.

If you ensure that the addresses you are adding are not already used, then you shouldn't have any problems, as long as you don't run out of processor memory.

Edit:

In Ti-soft you have to be sure the address isn't being used in a SFPGM or LOOP. Doing a search in ladder will not list these "hidden" usages.

Ken,

Thanks for the response. The situation you gave as an example may have heppened in my project, too. There seem to be gaps in the %Vnnnn addresses in some lists. There are also references to many items in some of the BASIC-like code behind some blocks. Yes blocks. There is no ladder here in this APT project, just blocks like the IEC-1131 language CSF (Control System Flowchart - think of rectangles connected with lines you arrange free-form).

I am still hoping someone can tell me how to see a list of all addresses used (since you say unused may be harder to do in a TI PLC).