Access Port; General Description; Access Port Operation; Local/Remote Console - HP 3000 Series Handbook

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Access Port
General Description
The Access Port is located on the Multifunction I/0 card. The Integrated Access Port is
designed for use with PA-RISC HP-PB I/0 base systems to provide a minimal level of remote
supportability for the systems. The Access Port gives the console operator the ability to read
system status and to generate system resets through the console terminal instead of through
the system's front panel display and switches. It also provides the ability to connect a second
console in parallel with the local console terminal. This "mirrored" console port is connected
to a modem through which the second or remote console is attached. This provides the same
system support functionality to a remote terminal as is available to a console operator sitting
next to the system.
Access Port Operation
Local/Remote Console
The I/0 card provides an interface for the host based PDC and card based IODC or the
operating system's I/0 driver to communicate with the console terminal and the support
modem. When the support modem is not being used for remote console operation, it is
available for use by the host system. When it is being used for remote console operation, the
modem port is connected in parallel with the system's console port, making it unavailable for
use as an independent terminal connection.
Access Port Functions
The Access Port may be considered as a type of support server. It acts as an agent to pass
characters between the front plane (terminal input and output) and the backplane (the host
system interface). At certain times, the Access Port may be given commands to suspend
character transfer between host and terminals to allow the console operator to interact
directly with the Access Port. This gives the operator the ability to check the operating status
of the host, enable or disable remote operator accesses, lock the remote support modem for
increased system security, force a system reset, or to initiate a Transfer of Control (TOC).
After the operator completes Access Port related tasks, communication with the host may be
resumed without loss of data.
Access Port Modes
Terminal ports connected to the Access Port may be in one of three modes:
Session Mode. Session mode is defined as a direct connection from the terminal to the host
system with the Access Port monitoring but not acting on any characters transmitted between
the terminal and the host.
Console Mode. Console mode is defined as a connection in which the Access Port monitors
the data being transferred and will take special action on some characters.
Control Mode.
Control mode is defined as a mode in which the terminal is in communication
with the Access Port only,
Functional Description 9-5