Which version of RST is used?
Does Intel SSD Toolbox show SMART info for the 530 SSD?
If no, this version of the RST driver lacks even the standard ATA pass-through (IOCTL_ATA_PASS_THROUGH) functionality which is required to access SMART data.
If yes, try another SMART tool to access SMART info for the HDDs.
Note that some versions of RST driver even supports SMART access for drives in a RAID configuration via CSMI (Common Storage Management Interface). Unfortunately Intel does not document which RST versions provide this functionality.