US 2002/0178283 A1 · Real-time networking protocol

Abstract

The present invention is an efficient protocol designed primarily for use in real-time communications systems involving the transmission of large numbers of short messages, allowing the user interface to have immediate and complete control over a device. The protocol utilizes a unique cascading token passing system for granting the right to control access to the transmission media. Sequential devices on a queue pass the token to each other in sequence, and a master device restarts the sequence each time the end of the sequence is reached. The master is also capable of giving priority to selected devices in the queue. The master device keeps track of skips in the queue (from failed or non-present devices) as well as the location of the end of the queue, and also periodically checks for new devices in the queue, checks the status of “dead” devices in the queue, and checks for devices added to the end of the queue. The master is capable of maintaining and reporting all such status information.

Claims11

Dependent claims

A frame for a message in a real-time network protocol for controlling the routing of information on a data communications network, comprising:

a preamble field having a single-byte pattern;
a single-byte control field;
a data count field having from one to three bytes;
a destination address field having from one to four bytes;
a source address field having from one to four bytes;
a data field having from zero to 254 bytes;
and
a 16-bit checksum field.

5 more elements

A method of communicating between a plurality of peer network devices in a queue on a data communications network, one of said devices being a master device, and each of the devices having the ability to pass a token for granting message transmission rights on the network, the method comprising the steps of:

a. generating a message within one of the plurality of peer network devices, the message including a single-byte control field, the single-byte control field including a grant bit that determines whether the said peer network device intends to pass the transmission rights token to the subsequent sequential peer network device on the queue;
b. sending the generated message to the data communications network;
c. the subsequent sequential peer network device determining from the message control field grant bit whether the token is to be passed to it;
d. passing the token according to the message control field grant bit;
e. the intended message destination device receiving and complying with the generated message;
f. repeating steps “a” through “e” above for each sequential peer network device until token is passed to the last device in the queue;
g. the master device passing the token from the last device to the first device in the queue;
h. continuously repeating steps “a” through “g.”

5 more elements

Dependencies are inferred from the claim text.

Real-time networking protocol

Life of this patent

Real-time networking protocol

Life of this patent

Abstract

Claims11