EXFO FTB-500 Guía Del Usario página 374

Data Types
Applicable Data Types for Output —IEEE 488.2
<NR1 NUMERIC RESPONSE DATA> (or <NR1>)

This data type will be used by a device to return positive or negative
integers.
Examples: 4, –23, 90
<NR2 NUMERIC RESPONSE DATA> (or <NR2>)

This data type will be used by a device to return positive or negative
real numbers (fixed-point numbers).
+
-
Examples: 23.45, 1.22, –4.55
366
+
-
<digit>
<digit>
.
<digit>
FTB-500