Browse Prior Art Database

Power Control Network Command/ Response Structure

IP.com Disclosure Number: IPCOM000121846D
Original Publication Date: 1991-Oct-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 6 page(s) / 227K

Publishing Venue

IBM

Related People

Berglund, NC: AUTHOR

Abstract

Described is the command/response structure for a computer system control network. This structure provides the means to quickly and efficiently collect power control status from each node in the network on a continual basis to provide the operating system with the earliest possible notification of events such as utility failures. In addition, the address structure provides the operating system with the most efficient means of addressing multiple nodes with one command.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 28% of the total text.

Power Control Network Command/ Response Structure

      Described is the command/response structure for a
computer system control network.  This structure provides the means
to quickly and efficiently collect power control status from each
node in the network on a continual basis to provide the operating
system with the earliest possible notification of events such as
utility failures.  In addition, the address structure provides the
operating system with the most efficient means of addressing multiple
nodes with one command.

      The logical structure of the network from the operating system
to the power control nodes in each rack is shown in Fig. 1.
Communication between a controller node coupled to the system CPU,
rack and slave power control nodes uses a command/response protocol.
A command is sent from the controller node to the selected
destination.  No further commands will be sent until a response has
been received or a time interval has expired.  One command may be
sent to one destination or to multiple destinations within one rack
or in multiple racks.  The command is delivered to each selected rack
in physical order, i.e., the order of interconnection, and to each
unit in numerical order.  Each destination receiving a command is
required to provide a response and a command is not forwarded to the
next node until the current one has responded.  The responses are
returned to the controller in "physical order", Unit 1 in Rack x,
Unit 2 in Rack x, Unit n in Rack x, Unit 1 in Rack y,
etc.

      The controller node provides the interface between the
operating system and the serial network.  The controller node
initiates network commands to collect status and manage the network.
The controller node also receives commands from the operating system
and either executes them directly or forwards them on the network to
the addressed node.  The controller node collects or builds the
command responses and returns them to the operating system.  The
controller node is master of the network and the only node that will
initiate serial communication.  Network protocol allows messages to
be directed to a single node, to multiple nodes in one rack, or to
all racks.

      Nodes in the network are located by their rack and unit
address.  Rack addresses are logical and assigned by the controller
node.  Unit addresses are physical and determined by the specific
port in the rack that the slave is connected to.  The controller node
is located in the primary rack and has a unit address just as the
slaves do, but since the controller node is the master of the network
and directly connected to the system, it is never addressed by unit
address.

      The rack node provides control of utility power for units in
the rack and serves as the router of serial network traffic.
Commands from the controller node are received by the rack and
forwarded to a slave in the rack or to another rack as directed by
the command ad dress.  T...