Agilent Technologies L4400 manual Querying the Sequence Definition, Executing a Sequence

Operating and Programming 3

Querying the Sequence Definition

Once you have defined a sequence, you can query the definition to review what SCPI commands have been assigned.

•The exact text specified in the original sequence definition is not preserved when the sequence is compressed/stored in memory. Therefore, the string returned may not be identical to the original string, but it will be functionally equivalent. If the specified sequence name is not currently stored in memory, an error is generated.

•The query command always returns the short form of the command header in all upper- case letters (e.g., “ROUT:CLOS” is returned instead of “ROUTE:CLOSE”). Channel numbers and channel range specifiers are returned as they were specified.

The following command returns a string containing the SCPI commands assigned to the specified sequence.

ROUT:SEQ:DEF? MYSEQ_1

The above command returns a string in the form (the quotes are also returned):

":ROUT:CLOS (@1001:1009);:ROUT:OPEN (@1001)"

Executing a Sequence

After you have defined a valid sequence, you can execute it to process the specified commands. If the specified sequence name is not currently stored in memory, an error will be generated.

•If you attempt to trigger a sequence while one is already executing, the trigger will be placed in a queue. When the trigger queue is full, a “trigger ignored” error will be generated.

•To abort a sequence execution, use the ROUTe:SEQuence:ABORt command or a Device Clear. When the sequence is terminated, the resultant instrument state will be determined by how much of the sequence had been executed when the ABORt/Device Clear was received. An ABORt command (system abort) executed from within a sequence will not terminate the sequence, but will abort a scan. The *RST and

SYSTem:PRESet commands will also abort a sequence execution prior to performing their own actions.

•When a sequence is defined, the specified commands are checked for proper syntax and absolute parameter range limits. If an error is detected during compilation, the entire sequence will be discarded. More extensive error checking, such as channel range expansion and validation, is performed when the sequence is executed.

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