User Manual

More About Oscilloscope Commands 35
Keysight InfiniiVision 1000 X-Series Oscilloscopes Programmer's Guide 787
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. 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 Keysight 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:
myScope.WriteString ":TIMebase:RANGe 0.5;POSition 0"