EXFO FTB-2 - Manual (Page 343)

Data Types
FTB-2 and FTB-2 Pro 333
Applicable Data Types for Output —IEEE 488.2

<BINARY NUMERIC RESPONSE DATA>
This data type will be used by a device to return integer representations
in binary (base 2).
Examples: #B11011110101, #B110100, #B0100

<STRING RESPONSE DATA>
This data type will be used by a device to return strings containing 7-bit
ASCII characters and especially when text has to be displayed since
even the non-printable characters are also returned.
Examples: "SCPI Commands", "SCPI ""Commands"""
# B
1
0
"
<inserted
"
>
"
<non-single
quote char>
"