EXFO FTB-2 - Manual (Page 426)

Communicating Through TCP/IP over Telnet
416 FTB-2 and FTB-2 Pro
Internal Commands of the TCP/IP over Telnet Protocol
BEGIN and END
To execute multiple SCPI commands, you must enclose them in BEGIN
and END blocks in a Telnet editor window.
Note: To execute a single command, simply type or paste the command in the
Telnet editor window.
Note: You cannot enclose internal commands in a BEGIN and END block, except
the ABORT BEGIN command.