Get 4 AO channels with PCI-6259 and SCXI-1302

Hello guys,

I am using a PCI-6259 which has 4 AO, all connections are made using SCXI-1302 terminal block. At the forum I found the 50-pin pinout. http://digital.ni.com/public.nsf/allkb/F27DD615660EB26786256F200046D2EB?OpenDocument

The way I see only channels 20 and 21 are AO, using channel 23 as ground for both. How do I get the other 2 AO channels the PCI-6259 enables?

Thanks for your help,

Daniel