The Standard Event register is cleared when:
You execute the *CLS (clear status) command.
You query the event register using the *ESR? (event status register)
command.
The Standard Event enable register is cleared when:
You execute the *ESE 0 command.
You turn on the power and have previously configured the function
generator using the *PSC 1 command.
The enable register will not be cleared at power-on if you have
previously configured the function generator using *PSC 0.
Chapter 4 Remote Interface Reference
The SCPI Status Registers
208