how many string lenght can "FileReadString" function collect out?

 
i try to read the string from a csv file that contains more than 4095 string lenght. But the string i got from the FileReadString function is always contain the lenght of 4095. Is this the highest limit of reading a the string from a file?
 
4095 - is lenght of internal file buffer. Try to read string in more than 1 pass and concatenate received strings
Reason: