More About Oscilloscope Commands 8

*WAI (see page 85)

Duplicate Mnemonics

Identical function mnemonics can be used in more than one subsystem. For example, the function mnemonic RANGe may be used to change the vertical range or to change the horizontal range:

:CHANnel1:RANGe .4

Sets the vertical range of channel 1 to 0.4 volts full scale.

:TIMebase:RANGe 1

Sets the horizontal time base to 1 second full scale.

:CHANnel1 and :TIMebase are subsystem selectors and determine which range is being modified.

Tree Traversal Rules and Multiple Commands

Command headers are created by traversing down the Command Tree (see page 535). A legal command header would be :TIMebase:RANGe. This is referred to as a compound header. A compound header is a header made of two or more mnemonics separated by colons. The mnemonic created contains no spaces.

The following rules apply to traversing the tree:

A leading colon (<NL> or EOI true on the last byte) places the parser at the root of the command tree. A leading colon is a colon that is the first character of a program header. Executing a subsystem command lets you access that subsystem until a leading colon or a program message terminator (<NL>) or EOI true is found.

In the command tree, use the last mnemonic in the compound header as the reference point (for example, RANGe). Then find the last colon above that mnemonic (TIMebase:). That is the point where the parser resides. Any command below that point can be sent within the current program message without sending the mnemonics which appear above them (for example, POSition).

The output statements in the examples are written using the Agilent VISA COM library in Visual Basic. The quoted string is placed on the bus, followed by a carriage return and linefeed (CRLF).

To execute more than one function within the same subsystem, separate the functions with a semicolon (;):

:<subsystem>:<function><separator><data>;<function><separator><data><ter

minator>

For example:

Agilent InfiniiVision 5000 Series Oscilloscopes Programmer's Reference

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Agilent Technologies 5000 Series manual Duplicate Mnemonics, Tree Traversal Rules and Multiple Commands