HP ESA-E Series Programmer's Manual page 36

HP ESA Status Registers
Using the Analyzer Status Registers
When you read the analyzer status byte register with a serial poll, the
NOTE
RQS bit is reset to 0. Other bits in the register are not affected.
Restarting a measurement (:INITiate command) can cause the
measuring bit to pulse low, which causes an SRQ if the status register
is configured to SRQ on end-of-measurement. To avoid this:
1. Set :INITiate:CONTinuous off.
2. Set/enable the status registers.
3. Restart the measurement (send :INITiate).
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