Sending data from Cyclone V FPGA to PC through USB Blaster

The command sequence below opens master number <id>, reads 16 bytes from it, writes them back and then closes it again.

set master  <id>]
set handle
set data 
master_write_memory $handle 0 $data
close_service master $handle

The master_read|write_memory commands are much faster than master_read|write_8|16|32 commands as the memory commands do the access as a whole block, the specified width commands do one or more accesses at the exact size specified which is much slower. You can use master_write_from_file if you have the data available in binary format in a local file.