Agilent Technologies E4406A VSA Putting Multiple Commands on the Same Line, Block Program Data

Programming Fundamentals

SCPI Language Basics

Block Program Data

Some parameters consist of a block of data. There are a few standard types of block data. Arbitrary blocks of program data can also be used.

<trace>	Is an array of rational numbers corresponding to
	displayed trace data. See FORMat:DATA for
	information about available data formats.
	A SCPI command often refers to a block of current trace
	data with a variable name such as: Trace1, TRACE2, or
	trace3, depending on which trace is being accessed.

<arbitrary block data> Consists of a block of data bytes. The first information sent in the block is an ASCII header beginning with #. The block is terminated with a semi-colon. The header can be used to determine how many bytes are in the data block. There are no units.

For example, suppose the header is #512320.

•The first digit in the header (5) tells you how many additional digits/bytes there are in the header.

•The 12320 means 12 thousand, 3 hundred, 20 data bytes follow the header.

•Divide this number of bytes by your current data format (bytes/data point), either 8 (for real64), or 4 (for real32). For this example, if you’re using real64 then there are 1540 points in the block.

Putting Multiple Commands on the Same Line

Multiple commands can be written on the same line, reducing your code space requirement. To do this:

•Commands must be separated with a semicolon (;).

•If the commands are in different subsystems, the key word for the new subsystem must be preceded by a colon (:).

•If the commands are in the same subsystem, the full hierarchy of the command key words need not be included. The second command can start at the same key word level as the command that was just executed.

64 Chapter 2