Regarding the PRI option for a 224: You would need the 12709 model for SS7 and ISDN PRI testing.

Which modules do you have equipped in the right side of your 224's chasis?

I don't normally use 224s, as I prefer the portable PRI testers myself (TPI570, Sunset, etc).

Feel free to send me a PM that provides me an email address, and I can send a couple of 224 pdf docs to you. There are also several different brochures and docs available thru different online searches.

Mike