R4SLS08 custom request

R4SLS08  I have another question: can the input value be stored in memory until we can read it and then erase it? We use this card in medical systems and we can't lose the input value if port 485 fails. 

can the input value be stored in memory until we can read it and then erase it? We use this card in medical systems and we can't lose the input value if port 485 fails.