HP 8753E Programming And Command Reference Manual page 25

EOI (End or Identify)
1-18 HP-IB Progmnmi ng and Command Reference Guide
(pressing ILocal) returns the device
to front-panel operation). When this
line is set false (high), the bus and all
of the connected devices return to
local operation.
This line is used by a talker to
indicate the last data byte in a
multiple-byte transmission, or by
an active controller to initiate
a parallel-poll sequence. The
analyzer recognizes the EOI line as
a terminator, and it pulls the EOI
line with the last byte of a message
output (data, markers, plots, prints,
error messages). The analyzer does
not respond to parallel poll.