KRC2s generally have two empty slots for adding KSD modules (maximum of 8 axes). You have to select a KSD that has sufficient current rating for your motor. The KSD-32 appears to be correct for the motor you've stated:
The KRC typically already has the power cabling for the KSDs run -- there should be some cables routed to the empty KSD slots labelled N7 and N8. You want to attach the N7 cables -- use the existing KSD connections as a reference. KSDs all wire up the same.
You will need to obtain an Interbus cable to connect from KSD6 to KSD 7. See the short white Rj45 cables that link each KSD to the KSD "downstream".
You will need two sets of servo power cabling: one set that plugs into the KSD on one end, and terminates in a large connector designed to mount to the lower bulkhead of the KRC2, alongside the X20, X11, etc connectors. Then, there's a simple cable that runs from that new bulkhead connector to the motor -- this cable comes in multiple lengths.
You will also need a Resolver cable. These come in multiple lengths. However, the Resolver cable does not connect to the KRC2. Instead, it runs from the smaller connector on the motor to the RDC card in the base of the KR arm. The RDC box typically has one or two removable plugs that can be replaced with cable glands to pass the A7 and A8 RDC cables through. The RDC cables terminate in a barrel connector on the motor end, and a flat connector on the RDC end. A standard RDC2 card can support up to 8 servos:
Your RDC card should already have 6 of these sockets (the row on the right) occupied. The first empty one should be for A7.
After the hardware is complete, you will need to configure your new axis. KSS 5.6 provides a nice External Axis configurator
