US 7,065,583 B2 · System and associated suppression assembly for limiting electromagnetic emissions in network devices communicating via a network bus

Abstract

A network system includes a network having a network bus, such as unshielded differential twisted-pair wires, electrically connected to a plurality of remote devices, and a network controller for digitally directing transmissions with the remote devices via the network bus. The network system also includes a plurality of network device interface elements adapted to interconnect the network controller with respective remote devices via the network bus. Each network device interface element is capable of transmitting and receiving messages via the network bus. And to at least partially limit electromagnetic emissions from the respective network device interface element and/or the respective remote device, each network device interface element includes a suppression assembly. Additionally, each network device interface element can include a transceiver and a processing element, with the suppression assembly electrically connected between the transceiver and the network bus.

Claims35

Dependent claims

A network system comprising:

a network comprising:
a network bus electrically connected to at least one network device;
and
a network controller for directing conummications with the at least one network device via said network bus, wherein said network controller is capable of selectively operating in either mode selected from the group consisting of a synchronous mode and an asynchronous mode;
and
at least one suppression assembly electrically connected between said network bus and respective network devices, wherein each suppression assembly is capable of limiting electromagnetic emissions from the respective network devices communicating via said network bus, and wherein each suppression assembly comprises:
an isolation transformer including a primary coil located proximate a respective network device and a secondary coil located proximate said network bus, wherein the primary coil and secondary coil include a primary center tap and a secondary center tap, respectively;
and
a resistor electrically connected between the secondary center tap and a ground.

6 more elements

A network system comprising:

a network comprising:
a network bus electrically connected to a plurality of remote devices;
and
a network controller for digitally directing transmissions with the plurality of remote devices via said network bus;
and
a plurality of network device interface elements adapted to interconnect said network controller with respective remote devices via said network bus, each network device interface element including a suppression assembly capable of at least partially limiting electromagnetic emissions from at least one of the respective network device interface element and the respective remote device, wherein each suppression assembly comprises an isolation transformer, wherein each network device interface element is capable of transmitting and receiving messages via said network bus, wherein said network device interface element is capable of determining if clock signals are provided with messages received via said network bus such that said network device inteitce element is capable of transmitting messages in either mode selected from the group consisting of a synchronous mode and an asynchronous mode based upon the determination.

3 more elements

A network device interface element adapted to interconnect a network controller with an associated remote device via a network bus, the network device interface element comprising:

a transceiver capable of transmitting and receiving messages via the network bus;
a processing element for providing commands to the associated remote device in response to messages received by said transceiver and for receiving data from the associated remote device, wherein said network device interface element is capable of determining if clock signals are provided with messages received by said transceiver such that the network device interface is capable of transmitting messages in either mode selected from the group consisting of a synchronous mode and an asynchronous mode based upon the determination;
and
a suppression assembly adapted to at least partially limit electromagnetic emissions from said transceiver and said processing element, said suppression assembly comprising:
an isolation transformer;
a common mode choke electrically connected to the network bus between said isolation transformer and the network bus;
and
a low pass filter electrically connected between said transceiver and said isolation transformer.

5 more elements

Dependencies are inferred from the claim text.

System and associated suppression assembly for limiting electromagnetic emissions in network devices communicating via a network bus

Life of this patent

System and associated suppression assembly for limiting electromagnetic emissions in network devices communicating via a network bus

Life of this patent

Abstract

Claims35