EXFO FTB-2 Guide De L'utilisateur page 435

Data Types
Applicable Data Types for Output —IEEE 488.2
<NR3 NUMERIC RESPONSE DATA> (or <NR3>)

This data type will be used by a device to return positive or negative
exponential numbers (floating-point numbers).
+
.
<digit> <digit>
-
+
E
<digit>
-
Examples: 4.3E–3, –8.9456E8, 123E–5
419
FTB-2/FTB-2 Pro and FTB-4 Pro