US 5,886,992 AGranted

Frame synchronized ring system and method

AssigneeValtion Teknillinen Tutkimuskeskus

InventorsK. Pertti T. Raatikainen, Juha E. Zidbeck, Olli Martikainen

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Abstract

A device-implemented method of data communications in a communications network is provided. A particular node which has data information to send is granted a turn when an incoming request signal is in an "off" state. An empty frame is captured and a frame of data information is sent in a downstream direction on the communication network when the particular node is granted a turn. An outgoing request signal is set in an "off" state when the empty frame is captured. The outgoing request signal is set in an "on" state when the empty frame is not captured and a turn has been granted. The outgoing request signal is set in an "on" state when the incoming request signal is in an "on" state and an incoming frame is not empty. The outgoing request signal preferably is sent in an upstream direction on the communication network where the upstream direction is different from the downstream direction on the communication network. A data communication network node and a communication network, which operate in accordance with the above-described method, also are provided.

Claims29

Dependent claims

A device-implemented method of data communication in a communication network, comprising the steps of:

(a) granting a turn, during a bus clock cycle, to a particular node having data information ready to send when an incoming request signal is in an "off" state;
(b) emptying a frame being received at the particular node, during the bus clock cycle, when the received frame is addressed only to the particular node while simultaneously transmitting a frame of data information ready to be sent by the particular node, during the bus clock cycle;
(c) capturing an empty frame at the particular nodes, during the bus clock cycle, and sending a frame of data information in a downstream direction on the communication network, during the bus clock cycle, when the particular node is granted a turn;
(d) setting an outgoing request signal in an "off" state at the particular node, during the bus clock cycle, when the empty frame is captured;
(e) setting the outgoing request signal in an "on" state at the particular node, during the bus clock cycle, when the empty frame is not captured and a turn has been granted;
and
(f) setting the outgoing request signal in an "on" state at the particular node, during the bus clock cycle, when the incoming request signal is in an "on" state and an incoming frame is not empty, the outgoing request signal being sent in an upstream direction on the communication network, the upstream direction being different from the downstream direction on the communication network.

4 more elements

A device-implemented method of data communication in a communication network, comprising the steps of:

(a) setting a turn flag to false for a particular node, if the turn flag has an undetermined state value;
(b) setting a frame available flag to true, if an incoming frame to the particular node is empty;
(c) setting the frame available flag to false, if an incoming frame to the particular node is not empty;
(d) emptying a frame being received at the particular node when the received frame is addressed only to the particular node while simultaneously transmitting a frame of data information ready to be sent by the particular node, and setting the frame available flag to true after emptying the frame;
if the particular node does not have data information to send,
(e) setting an outgoing request signal in an "on" state at the particular node when an incoming request signal is in "on" state and an incoming frame is not empty;
(f) setting the outgoing request signal in an "off" state at the particular node when the incoming request signal is in "off" state;
if the particular node does have data information to send, and if the frame available flag is false,
(g) setting the turn flag to true, if the incoming request line is in an "off" state;
(h) setting the outgoing request signal in an "on" state;
if the particular node does have data information to send, and if the frame available flag is true,
(i) setting the outgoing request signal in an "on" state, if the incoming request line is in an "on" state, an incoming frame is not empty, and the turn flag is false;
(j) setting the turn flag to true, if the incoming request line is in an "off" state and the turn flag is false;
and
(k) sending a frame of data information in a downstream direction on the communication network, setting the turn flag to false, and setting the outgoing request signal in an "off" state, if the turn flag is true, the outgoing request signal being sent in an upstream direction on the communication network, the upstream direction being different from the downstream direction on the communication network.

12 more elements

A data communication network node, comprising:

(a) receiving means for receiving an incoming request signal and a frame from a communication network during a bus clock cycle;
(b) buffer means, operatively coupled to the receiving means, for emptying the received frame, during the bus clock cycle, when the received frame is addressed only to the node while simultaneously transmitting a frame of data information ready to be sent by the particular node, during the bus clock cycle;
(c) processing means, operatively coupled to the receiving means and the buffer means, for:
(i) granting a turn to the node, during the bus clock cycle, when the node has data information ready to be sent and the received incoming request signal is in an "off" state;
(ii) replacing the received frame with data information ready to be sent from the node, during the bus clock cycle, when the received frame is empty and the node has a turn such that, if the frame is emptied into the buffer means, the received frame is replaced with data information to be sent from the node when the node has a turn;
(iii) setting an outgoing request signal in an "off" state, during the bus clock cycle, when the frame is replaced;
(iv) setting the outgoing request signal in an "on" state, during the bus clock cycle, when the frame is not replaced and a turn has been granted;
and
(v) setting the outgoing request signal in an "on" state, during the bus clock cycle, when the incoming request signal is in an "on" state;
and
(d) transmitting means, operatively coupled to the processing means, for transmitting the outgoing request signal in an upstream direction on the communication network and transmitting the frame in a downstream direction on the communication network, the upstream direction being different from the downstream direction on the communication network.

8 more elements

Dependencies are inferred from the claim text.