EXFO FTB-2 - Manual (Page 327)

FTB-2 and FTB-2 Pro 317
B Data Types
The following section provides an overview of the most common data
types that may appear in EXFO’s documentation on commands and
queries. The information is supplied for guidance only.
For more detailed information, please refer to IEEE 488.2 and SCPI
standards.
Data types are divided into two groups: <PROGRAM DATA> for the types
that are used when you want to send messages to a device and
<RESPONSE DATA> for the types that are used when a device sends
responses to the controller.
The data types are presented in graphics often referred to as “railroad
diagrams”. The following example illustrates how to interpret such
diagrams.
<Upper/lower
case alpha>
<Upper/lower
case alpha>
_
<digit>
Entry Exit
The reverse arrow indicates that
the item specified in the box can
be repeated several times
The splitting arrow indicates a
choice of items
In circles: literal
items (to be
typed as such) In boxes: syntactic
items (use the
elements to which
they refer)