EXFO FTB-1v2 Guide De L'utilisateur page 494

Communicating Through TCP/IP Over Telnet
Internal Commands of the TCP/IP over Telnet Protocol
Examples
Notes
482
If the command is not executed successfully, a

possible reason could be that the provided
information does not correspond to a valid LINS.
On all platforms except IQS-600 and FTB-500,

CLOSE LINS does not prevent another session
from accessing the instrument using a direct LINS
command.
CLOSE LINS
FTB-1v2 and FTB-1v2 Pro