Sending Multiple Commands. Agilent Technologies 8712ES, 8714ET, 8714ES, 8712ET

Introduction to SCPI

Sending Multiple Commands

Sending Multiple Commands

Multiple commands can be sent within a single program message by separating the commands with semicolons. For example, the following program message — sent within an HP BASIC OUTPUT statement — turns on the marker reference and moves the main marker to the highest peak on the trace:

OUTPUT 716;"CALCULATE:MARKER:MODE

RELATIVE;:CALCULATE:MARKER:MAXIMUM"

One of the analyzer's command parser main functions is to keep track of a program message's position in the command tree. This allows the previous program message to be simplified. Taking advantage of this parser function, the simpler equivalent program message is:

OUTPUT 716;"CALCULATE:MARKER:MODE RELATIVE;MAXIMUM"

In the first version of the program message, the semicolon that separates the two commands is followed by a colon. Whenever this occurs, the command parser is reset to the base of the command tree. As a result, the next command is only valid if it includes the entire mnemonic path from the base of the tree.

In the second version of the program message, the semicolon that separates the two commands is not followed by a colon. Whenever this occurs, the command parser assumes that the mnemonics of the second command arise from the same branch of the tree as the final mnemonic of the preceding command.

MODE , the final mnemonic of the first command, arises from the MARKER branch. So MAXIMUM , the first mnemonic of the second command, is also assumed to arise from the

MARKER branch.

The following is a longer series of commands — again sent within

HP BASIC OUTPUT statements — that can be combined into a single program message:

OUTPUT 716;"CALCULATE:MARKER:STATE ON"

OUTPUT 716;"CALCULATE:MARKER:MODE RELATIVE"

OUTPUT 716;"CALCULATE:MARKER:MAXIMUM"

OUTPUT 716;"CALCULATE:MARKER:FUNCTION:TRACKING ON"

The single program message is:

OUTPUT 716;"CALCULATE:MARKER:STATE ON;MODE

RELATIVE;MAXIMUM;FUNCTION:TRACKING ON"

Programmer’s Guide 9-7