MC664 in theory can support the P873 though we do not at present have any customers using that combination. The P873 will support 6 axes (2 x 3). You do not need feature codes, the axes are included in the price.

There was no special build of MC224 firmware for the SLM.

The main thing to watch for is that Motion Perect 3, 4 and 5 have no SLM support. So you must take the setup program out of the MC224 and modify it by hand. The ATYPE is different for SLM in the MC664 for example.