EXFO FTB-500 Guía Del Usario página 262

Using FTB Products in an Automated Test Environment
SCPI Command Structure
Item
<mnemonic> Element used in the construction of certain data types and program
messages.
In the diagram above,


< > Text appearing between angled brackets specifies the command
parameter to be sent or the response you will receive from an
instrument.
Do not include angled brackets in your program message.
| Indicates that one, and only one, value must be selected from the
available choices.
Example: If the list is 0|1, you can only select 0 or 1.
Do not include the pipe character in your program message.
{ } Indicate that the enclosed parameters can appear 0 to n times when the
command is used.
Do not include braces in your program message.
: Mandatory to separate keywords. Can be omitted at the beginning of a
program message. For example, you can use either :SYST:ERR or
SYST:ERR.
254
<Upper/lower
case alpha>
"<Upper/lower case alpha>" corresponds to ASCII character codes
(65 to 90 and 97 to 122, in decimal).
"_" corresponds to an underscore character (code 95, in decimal).
Meaning
<Upper/lower
case alpha>
_
<digit>
FTB-500