Hello Andy,
After looking at the product page of the device, I think you will need need a 50-pin IDC to 50-pin edge connector ribbon cable. Something like this. From here you can use a Breakout board to connect it to the SCB-68.
I don't believe that this would be the best design for your application. I would instead use a custom cable to connect the SSR I/O modules to the PCI-6224. I think this would reduce the amount of losses induced by multiple connections.
