You must use the Block Transfer Read (BTR) and Block Transfer Write (BTW) instructions with those modules. Learn to use those instructions from the RSLogix 500 Online Help or the Instruction Set Reference.
The 1794-IE12 uses 13 read (BTR) and 2 write words (BTW).
The 1794-OE12 uses 1 read (BTR) and 14 write words (BTW).
The Installation Instructions give the layout of those data blocks.