Each digit in the permissions is a flag that signifies what is allowed to be done with your file, reading, writing or executing.

Here is a breakdown of how it works:

Permissions:
1 – can execute
2 – can write
4 – can read

The octal number is the sum of those free permissions, i.e.
3 (1+2) – can execute and write
6 (2+4) – can write and read

Position of the digit in value:
1 – what owner can
2 – what users in the file group(class) can
3 – what users not in the file group(class) can

Examples:
chmod 600 file – owner can read and write
chmod 700 file – owner can read, write and execute
chmod 644 file – owner can read and write, all can read
chmod 777 file – all can read, write and execute

If you would like to keep the permissions on 600, edit the automated profile in Auto FTP Manager, and change the FTP login and password to the owner of the file and directory your are transferring from.