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Optical Link Control Protocol for Remote Apparatuses with Automatic Power On/Off Function

IP.com Disclosure Number: IPCOM000113212D
Original Publication Date: 1994-Jul-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 98K

Publishing Venue

IBM

Related People

Ishikawa, H: AUTHOR [+3]

Abstract

Disclosed is a method to turn on/off the power of remote apparatuses which are connected to a main system unit via optical links. The principle of the method is that the power of the remote apparatus is kept turned on if and only if the apparatus is receiving valid communication data on the link. No explicit commands to control the remote power is necessary but a stand-by power supply for the receiver in the remote apparatus is assumed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Optical Link Control Protocol for Remote Apparatuses with Automatic
Power On/Off Function

      Disclosed is a method to turn on/off the power of remote
apparatuses which are connected to a main system unit via optical
links.  The principle of the method is that the power of the remote
apparatus is kept turned on if and only if the apparatus is receiving
valid communication data on the link.  No explicit commands to
control the remote power is necessary but a stand-by power supply for
the receiver in the remote apparatus is assumed.

      It is a very common demand to turn on/off the power of
apparatuses located at a distant place in response to a main system
unit.  A conventional approach is to equip a copper line along with a
communication link to the remote apparatus, with which a relay for
the remote power is turned on/off.  Although the simplicity of the
conventional approach, it does not fit to the recently proliferating
optical communication links.  A simple durable protocol for these
optical links without using a copper line is proposed.

      Suppose the optical link uses a synchronous communication
method, that is, the data over the link is encoded in a certain way
and filler codes are padded during no meaningful data is transferred
from the main unit.  Also suppose a stand-by power supply is equipped
to the receiver circuit of the optical link at the remote side and
the main power for the remote apparatus is turned on/off with this
link controller.

Power-On Sequence:

      0) At first the main unit is not turned on and no valid codes
are transmitted to the remote side.  The receiver at the remote side
is in a stand-by state and always verifying the receiving data.
Since the received data is not valid codes, the main power of the
remote unit is not turned on.

      1) When the main unit is turned on, it begins to send valid
communication codes to the remote side.  The receiver at the remote
side verifies the codes for a certain duration and then turns on the
main power of the remote apparatus.  If the verification is not
satisfied, it remains in the stand-by state.

      2) After the main power of the remote apparatus is turned on,
the link controller at the remote side begins to send valid
communication codes to the main unit.  The receiver of the main unit
verifies them for a certain duration and then recognizes the remote
apparatus successfully turned on.

Power-Off Sequence:

      0) The filler codes are padded during no meaningful data is
transmitted over the link and the receivers at both ends always
verify those codes on the link.  If the remote side detects errors
such as invalid code, wrong sequence of codes and time-out of
hand-shake communication, two situations must be...