EXFO FTB-500 - Manual (Page 347)

Data Types
FTB-500 339
Applicable Data Types for Output —IEEE 488.2
Applicable Data Types for Output —IEEE 488.2

In the diagram above,

“NL” corresponds to ASCII character code 10, in decimal (0A in
binary)

“END^” corresponds to the last data byte of the message sent with
EOI = True and ATN = False

This data type will be used by a device to return short mnemonics
when a cannot be used. The
returned information is sent in the long form and in upper case.
Examples: TRIANGLEWAVE, NCONTINUOUS
NL END^