The X-board series are for I-7188XA, I-7188XB, I-7188XC, I-7188XG, I-7188EG, I-7188EX and uPAC-7186EX Series (uPAC-7186EX, uPAC-7186PEX, uPAC-7186EG, uPAC-7186EX-FD, uPAC-7186EX-SM).
Above one µPAC can plug only one X-board.
X305D is a 8-channel Non-Isolation Analog Input and 2-channel Digital Input and 2-channel Digital Output X-board for I-7188XB, I-7188XG, I-7188EX, I-7188EG and uPAC-7186EX Series.