Subsystem Commands
Each subsystem set of commands are grouped together under a common
node of the command tree, such as the :TIMebase commands. Only one
subsystem may be selected at any given time. When the instrument is initially
turned on, the command parser is set to the root of the command tree, so no
subsystem is selected.
Tree Traversal Rules
Command headers are created by traversing down the command tree. A legal
command header from the command tree would be :TIMebase:RANGe. This
is called a compound header. A compound header consists of two or more
mnemonics separated by colons. The created mnemonic contains no spaces.
The following rules apply to traversing the tree:
•
A leading colon or a <program message terminator> (either an <NL> or
EOI true on the last byte) places the parser at the root of the command
tree. The leading colon is the first character of a program header.
•
Executing a subsystem command places the logic analyzer in that
subsystem until a leading colon or a <program message terminator> is
found. In the command tree, use the last mnemonic in the compound
header as a reference point (for example, RANGe). Then find the last
colon above that mnemonic (TIMebase:). That is the point where the
parser resides. You can send any command below that point within the
current program message (for example, DELay) without sending the
mnemonics that appear above them.
Examples
The OUTPUT statements in the examples are written using HP BASIC. The
quoted string is placed on the bus, followed by a carriage return and linefeed
(CRLF).
Example 1:
OUTPUT 707;":TIMEBASE:RANGE 0.5 ;DELAY 0"
The colon between TIMEBASE and RANGE is necessary because
TIMEBASE:RANGE is a compound command. The semicolon between the
RANGE command and the DELAY command is the required program
message unit separator. The DELAY command does not need TIMEBASE
preceding it because the TIMEBASE:RANGE command sets the parser to the
TIMEBASE node in the tree.
Programming and Documentation Conventions
The command tree
54
Summary of Contents for 54620A
Page 6: ...6 ...
Page 9: ...1 Introduction to Programming ...
Page 21: ...2 Programming Getting Started ...
Page 35: ...3 Programming over HP IB ...
Page 40: ...40 ...
Page 41: ...4 Programming over RS 232 C ...
Page 48: ...48 ...
Page 49: ...5 Programming and Documentation Conventions ...
Page 53: ...Programming and Documentation Conventions The command tree 53 ...
Page 60: ...60 ...
Page 61: ...6 Status Reporting ...
Page 63: ...Status Reporting Data Structures Figure 4 Status Reporting 63 ...
Page 68: ...68 ...
Page 69: ...7 Installing and Using the Programmer s Reference ...
Page 76: ...76 ...