Greetings,
The PCI-6024E can be used with the SCXI-1531, but the PCI-6013 cannot. Furthermore, you will need an SCXI chassis to house the 1531 (you may have already known this). The SCXI-1000 can hold up to four modules. Below is a link to information concerning the SCXI product line:
http://sine.ni.com/apps/we/nioc.vp?cid=1604〈=US
Good luck with your application.
Spencer S.