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Download Agilent Technologies 2000 X-Series Technical data
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More About Oscilloscope Commands 37 Valid Command/Query Strings • "Program Message Syntax" on page 791 • "Duplicate Mnemonics" on page 795 • "Tree Traversal Rules and Multiple Commands" on page 795 Program Message Syntax To program the instrument remotely, you must understand the command format and structure expected by the instrument. The IEEE 488.2 syntax rules govern how individual elements such as headers, separators, program data, and terminators may be grouped together to form complete instructions. Syntax definitions are also given to show how query responses are formatted. The following figure shows the main syntactical parts of a typical program statement. 3URJUDP0HVVDJH ":DISPLAY:LABEL ON" ,QVWUXFWLRQ+HDGHU 6HSDUDWRU 3URJUDP'DWD Instructions (both commands and queries) normally appear as a string embedded in a statement of your host language, such as Visual Basic or C/C++. The only time a parameter is not meant to be expressed as a string is when the instruction's syntax definition specifies <block data>, such as <learn string>. There are only a few instructions that use block data. Program messages can have long or short form commands (and data in some cases — see "Long Form to Short Form Truncation Rules" on page 792), and upper and/or lower case ASCII characters may be used. (Query responses, however, are always returned in upper case.) Instructions are composed of two main parts: • The header, which specifies the command or query to be sent. • The program data, which provide additional information needed to clarify the meaning of the instruction. Instruction Header The instruction header is one or more mnemonics separated by colons (:) that represent the operation to be performed by the instrument. ":DISPlay:LABel ON" is a command. Queries are indicated by adding a question mark (?) to the end of the header, for example, ":DISPlay:LABel?". Many instructions can be used as either commands or queries, depending Agilent InfiniiVision 2000 X-Series Oscilloscopes Programmer's Guide 791
