User`s guide

12 Upper Limit Failed 4096 upper limit in limit test.
13 Not Used Not Used "0" is returned.
14 Memory Overflow 16384
Reading memory is full.
One or more (oldest)
readings have been
lost.
15 Not Used Not Used "0" is returned.
Once a bit is set, it remains set until cleared by reading the event register
or the *CLS (clear status) command.
The *RST, SYSTem:PRESet, STATus:PRESet, and *PSC commands have no
effect on this register.