Schweitzer Engineering Laboratories, Inc.

Srinivas Achanta

David E Whitehead

Shankar V Achanta

Raymond W Rice

Manodev J Rajasekaran

Jerry J Bennett

David M Rector

Hidayatullah Ahsan

Ian C Ender

Damian Sanchez Moreno

M Wesley Kunzler

A fixed latency configurable tap or fixed-tap digital filter may filter a signal in a fixed amount of time, regardless of the number of taps. The filter may include one or more of a clock, a plurality of registers in a shift register, an adder, an accumulator, and/or a scaler. In at least one embodiment, a running average may be maintained as samples are received such that the latency remains fixed with a constant number of clock cycles.

Fixed latency configurable tap digital filter

The time signal verification and distribution device disclosed herein verifies and distributes a time signal to consuming devices. The device determines a time quality status of a first and second time signal, calculates a difference between a first and a second time signal, and compares the difference to a predetermined threshold. Based on the time quality status and the comparison, the time signal verification and distribution device distributes a time signal to a plurality of time signal consuming devices. Exceeding the predetermined threshold may indicate a spoofing attack or other problem with the time signals.

Time signal verification and distribution

The present application discloses a time distribution device capable of providing a synchronized time signal to a plurality of end devices connected to the time distribution device with cables of various lengths. The time distribution device may receive a time signal, generate a time reference based on the received time signal, compensate the time reference for hardware delay, and overcompensate the time reference for a delay caused by a maximum cable length. Prior to being distributed to various end devices, each being connected with the time distribution device by cables of varying length, this overcompensated time reference may then be delayed by an amount based on the cable length connecting each respective end device such that the arrival of each of the synchronized time references at the various end devices is synchronized.

Delay compensation for variable cable length

Disclosed is a network communication switch that facilitates reliable communication of high priority traffic over lower priority traffic across all ingress and egress ports. The network communication switch may monitor the frame storage buffer regardless of egress port, and when the frame storage buffer reaches a predetermined level, the switch may discard lower priority frames from the most congested port. When the frame storage buffer reaches a second predetermined level, the switch may discard lower priority frames before they are stored according to egress port. The network communication switch may further monitor ingress frames for priority, and assign priority to frames according to pre-assigned priority, ingress port, and/or frame contents.

Network device

Disclosed herein are a variety of systems and methods for correcting for propagation delay in time signals used in connection with an electric power generation and delivery system. According to various embodiments, a device consistent with the present disclosure may determine an estimated propagation delay between an accurate time source and a receiving device. The propagation delay may be determined based on a variety of transmission parameters including, for example, communication channel type and/or length. A corrected time signal may be generated by advancing a reference incitation such as an 'on-time' reference and/or 'start-of-second' reference included in the time signal by an amount associated with the propagation delay. The corrected time signal may then be transmitted to the receiving device.

Growing community of inventors

Pullman, WA, United States of America

Srinivas Achanta