The thing to keep in mind is the TD-171 card has CID to only one extension, along with being a -3 or later. The 824 has CID to SLT's if the KSU has a CID card on the trunks. The package switch comes with the card.
I've got the TD-170 module for the extra 8 extensions, but no CID. And, being a -0 KSU, I guess I can't use the TD-171 anyway, so I may be out of luck.
Is the CID card you refer to the KX-TD193? According to Panasonic's
mini-catalog, it "ALLOWS CALLER ID INFORMATION TO APPEAR ON THE DISPLAY OF PROPRIETARY TELEPHONES AND SMDR PRINTER." I have that now, so I must have that card installed (I haven't popped the cover off the KSU to look.)
Ah ha...just noticed in the KX-TD170 description in that same doc that the TD170 "PROVIDES CALLER ID FOR SLT PHONE ON THE FIRST PORT." I didn't try any of the expansion ports with my analog CID phone. Maybe that's all I need?