HP HP 8753E, User Manual, Page: 635 / 699

ATN (Attention)
SRQ (Service Request)
The active controller uses this line to define whether
the information on the data bus is command-oriented or
data-oriented. When this line is true (low), the bus is in the
command mode, and the data lines carry bus commands. When
this line is false (high), the bus is in the data mode, and the
data lines carry device-dependent instructions or data.
This line is set true (low) when a device requests service
and the active controller services the requesting device. The
network analyzer can be enabled to pull the SRQ line for a
variety of reasons such as requesting control of the interface,
for the purposes of printing, plotting, or accessing a disk.
REN (Remote Enable)
EOI (End or Identify)
This line is used exclusively by the system controller. When this
line is set true (low), the bus is in the remote mode, and devices
are addressed by the controller to either listen or talk. When
the bus is in remote mode and a device is addressed, it receives
instructions from the system controller via HP-IB rather than
from its front panel (pressing returns the device to
front-panel operation). When this line is set false (high), the
bus and 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, error messages).
The analyzer does not respond to parallel poll.
Number of Interconnected Devices:
15 maximum.
Interconnection Path Cable Length: 20 meters maximum or 2 meters per device
(whichever is less).
Message Transfer Scheme:
Byte serial, bit parallel a synchronous data
transfer using a handshake system.
Data Rate:
Maximum of 1 megabyte-per-second over the
specified distances with drivers. Actual
data rate depends on the transfer rate of the
slowest device connected to the bus
Address Capability:
Multiple-Controller Capability:
Primary addresses: 31 talk, 31 listen. A
maximum of 1 talker and 14 listeners can be
connected to the interface at given time.
In systems with more than one controller (like
this instrument), only one controller can be
active at any given time. The active controller
can pass control to another controller, but only
the system controller can assume unconditional
control. Only one system controller is allowed.
Compatible Peripherals