Keysight Technologies E5260 Series Programming Manual page 203

Remarks If you start an operation that you may want to abort, do not send any command after
the command or command string that starts the operation. If you do, the AB
command cannot enter the command input buffer until the intervening command
execution starts, so the operation cannot be aborted. In this case, use the device clear
(HP BASIC CLEAR command) to end the operation.
If the AB command is entered in a command string, the other commands in the
string are not executed. For example, the CN command in the following command
string is not executed.
OUTPUT @E5270;"AB;CN"
During sweep measurement, if the E5260/E5270 receives the AB command, it
returns only the measurement data obtained before abort. Then the dummy data is
not returned.
For the quasi-pulsed spot measurement, the E5260/E5270 cannot receive any
command during the settling detection. So the AB command cannot abort the
operation, and it will be performed after the settling detection.
Keysight E5260/E5270 Programming Guide, Edition 4
Command Reference
Command Reference
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