CPU 319-3 PN/DP- ''Area length error when reading''- “Event ID 16#2522”

Hi Varadharajan.S 

not enough information to help I'm afraid and the question remains what error value you get in the STATUS word of the Modbus Blocks?

Note that the outputs values of these Blocks are only valid for one scan so add capture logic to your program to grab the STATUS value if the error bit is true and the use the manual to see what is going on.