Don't know if this will work, but there is one possibility pointed out in the documentation on the low-level file read function:
"
pos mode, together with pos offset, specifies where the read operation should begin reading.
0 pos mode indicates that the read operation should begin at the beginning of the file plus pos offset.
1 pos mode indicates that the read operation should begin at the end of the file plus pos offset.
2 pos mode indicates that the read operation should begin at the current location of the file mark plus pos offset.
If the computed location does not exist in the file, for example, pos mode = 0 and pos offset = -10, the file mark does not move, no data is read, and the function returns an error.
If you wire pos offset, po
s mode defaults to 0, and the offset is relative to the beginning of the file. If you do not wire pos offset it defaults to 0, pos mode defaults to 2, and the read operation starts at the current file mark. Leave these inputs unwired if you want to read the data following the most recently read data.
pos offset specifies how far from the location specified by pos mode to start reading. If the file specified by refnum is a datalog file, you express pos offset in terms of records of the data type stored in the datalog file; otherwise, you express pos offset in units of bytes. pos offset defaults to 0 if unwired."
The really interesting part is the last sentence:
"
Leave the pos mode and pos offset inputs unwired if you want to read the data following the most recently read data."
Because you are therefore not entering an offset explicitly, you might be able to sidestep the file size issue. Attached is a VI that might do what you need--let me know how this turns
out...
Mike..
