US 2007/0047588 A1 · Communication system and slave and repeater units therefor

Abstract

A communication system is formed with a master unit having a communication function and at least one slave unit also having a communication function connected by a network including a bus. Repeater units are inserted on the network between the master unit and the slave unit in one or more stages. As the master unit transmits request frames downstream through the network to the slave unit, the slave unit control the timing of transmitting the response frames in response successively such that the master unit receives the response frames without waiting in between regardless of repeater delay times of each of the returned response frames determined by the number of stages of the repeater units. Each communication frame that is transmitted through the network contains identification data indicative of its type and each repeater unit serves to repeat certain types of received frames only in the upstream direction.

Claims11

Dependent claims

A communication system comprising:

a master unit which is a programmable controller having a communication function;
at least one slave unit which is an I/O terminal unit having a communication function and connected to said master unit by a network;
and
repeater units inserted on said network between said master unit and said at least one slave unit in one or more stages;
wherein said master unit serves to transmit request frames in a downstream direction through said network to said at least one slave unit, response frames being transmitted from said at least one slave unit each in response to a corresponding one of said request frames;
wherein said repeater units serve to repeat said response frames only in an upstream direction through said network which is opposite said downstream direction, and
wherein communication frames of various types that include both said request frames and said response frames each contain identification data indicative of the type thereof.

4 more elements

A communication system comprising:

a master unit which is a programmable controller having a communication function;
at least one slave unit which is an I/O terminal unit having a communication function and connected to said master unit by a network;
and
repeater units inserted on said network between said master unit and said at least one slave unit in one or more stages;
wherein said network serves to transmit communication frames of various types therethrough, each of said communication frames containing identification data indicative of the type thereof;
wherein said repeater units serve to repeat some of said communication frames only in an upstream direction through said network, depending on the type thereof;
and
wherein said slave unit stores the number of stages of said repeater units between said slave unit and said master unit and transmits response frames successively in response to request frames received from said master unit such that said master unit receives said response frames without waiting in between regardless of repeater delay times of each of said returned response frames determined by said number of the stages of the repeater units.

5 more elements

Dependencies are inferred from the claim text.

Communication system and slave and repeater units therefor

Life of this patent

Communication system and slave and repeater units therefor

Life of this patent

Abstract

Claims11