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THE JOURNEY THROUGH TIME

Explore Black History

Explore the people, places, events, achievements, struggles and stories that shaped our journey.

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Civil Rights

Movements, leaders, victories and the continuing fight for equality.

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Black Inventors

Innovation, patents, science, technology and world-changing contributions.

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Sports

Pioneers, champions, Negro Leagues, records, activism and excellence.

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People

Meet the people whose lives, choices and achievements shaped the journey.

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Places

Black towns, communities, institutions and places where history happened.

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Events

Moments that changed communities, movements, institutions and the nation.

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MY'STORY

The MOVE Fire

This is a personal recollection on the Move fire on May 13, 1985 Philadelphia police fired thousands of rounds at the MOVE house, city officials approved dropping an explosive device on the roof, the resulting fire was allowed to burn, 11 people—including five children—died, and 61 homes were destroyed. Philadelphia City Council later called it a “brutal attack carried out by the City of Philadelphia on its own citizens” and acknowledged that no individual faced criminal consequences for the bombing. One timeline correction worth preserving for the BHP record: the major previous MOVE-police confrontation was August 8, 1978, about seven years before the bombing, not a year or two earlier. Officer James Ramp was killed, other police and firefighters were wounded, nine MOVE members were later convicted, and television cameras recorded police beating Delbert Africa during his arrest. The 1985 MOVE Commission later specifically criticized city planners for failing to adequately use lessons from that 1978 confrontation. And that actually strengthens the point you’re making: 1985 did not happen without precedent or institutional memory. There had already been a deadly confrontation with MOVE, years of conflict, negotiations and police involvement before Osage Avenue.

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BLACK FACTS
The Truths They Never Taught You...

The Violence That Helped Spark the NAACP

In August 1908, a white mob attacked Springfield, Illinois’s Black community, destroying homes and businesses and lynching two Black men. National outrage over the violence helped spur the movement that created the NAACP the following year.

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Wikipedia

ControlNet

ControlNet is an open industrial network protocol for industrial automation applications, also known as a fieldbus. ControlNet was earlier supported by ControlNet International, but in 2008 support and management of ControlNet was transferred to ODVA, which now manages all protocols in the Common Industrial Protocol family.

Features which set ControlNet apart from other fieldbuses include the built-in support for fully redundant cables and the fact that communication on ControlNet can be strictly scheduled and highly deterministic. Due to the unique physical layer, common network sniffers such as Wireshark cannot be used to sniff ControlNet packets. Rockwell Automation provides ControlNet Traffic Analyzer software to sniff and analyze ControlNet packets.

Version 1, 1.25 and 1.5

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Versions 1 and 1.25 were released in quick succession when ControlNet first launched in 1997. Version 1.5 was released in 1998 and hardware produced for each version variant was typically not compatible. Most installations of ControlNet are version 1.5.[1]

Architecture

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Physical layer

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ControlNet cables consist of RG-6 coaxial cable with BNC connectors, though optical fiber is sometimes used for long distances. The network topology is a bus structure with short taps. ControlNet also supports a star topology if used with the appropriate hardware. ControlNet can operate with a single RG-6 coaxial cable bus, or a dual RG-6 coaxial cable bus for cable redundancy. In all cases, the RG-6 should be of quad-shield variety. Maximum cable length without repeaters is 1000m and maximum number of nodes on the bus is 99. However, there is a tradeoff between number of devices on the bus and total cable length. Repeaters can be used to further extend the cable length. The network can support up to 5 repeaters (10 when used for redundant networks). The repeaters do not utilize network node numbers and are available in copper or fiber optic choices.

The physical layer signaling uses Manchester code at 5 Mbit/s.

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ControlNet is a scheduled communication network designed for cyclic data exchange. The protocol operates in cycles, known as NUIs, where NUI stands for Network Update Interval. Each NUI has three phases, the first phase is dedicated to scheduled traffic, where all nodes with scheduled data are guaranteed a transmission opportunity. The second phase is dedicated to unscheduled traffic. There is no guarantee that every node will get an opportunity to transmit in every unscheduled phase. The third phase is network maintenance or "guardband". It includes synchronization and a means of determining starting node on the next unscheduled data transfer. Both the scheduled and unscheduled phase use an implicit token ring media access method. The amount of time each NUI consists of is known as the NUT, where NUT stands for Network Update Time. It is configurable from 2 to 100 ms. The default NUT on an unscheduled network is 5 ms.

The maximum size of a scheduled or unscheduled ControlNet data frame is 510 Bytes.

Application layer

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The ControlNet application layer protocol is based on the Common Industrial Protocol (CIP) layer which is also used in DeviceNet and EtherNet/IP.

References

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  1. ^ "ControlNet PLC-5 Programmable Controllers" (PDF). Rockwell Automation. Retrieved 30 July 2016.
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Source: Wikipedia. Article content is retrieved live through the MediaWiki API.

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Wikipedia

ControlNet

ControlNet is an open industrial network protocol for industrial automation applications, also known as a fieldbus. ControlNet was earlier supported by ControlNet International, but in 2008 support and management of ControlNet was transferred to ODVA, which now manages all protocols in the Common Industrial Protocol family. Features which set ControlNet apart from other fieldbuses include the built-in support for fully redundant cables and the fact that communication on ControlNet can be strictly scheduled and highly deterministic. Due to the unique physical layer, common network sniffers such as Wireshark cannot be used to sniff ControlNet packets. Rockwell Automation provides ControlNet Traffic Analyzer software to sniff and analyze ControlNet packets.

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Wikipedia

ComfyUI

ComfyUI is an open-source, node-based program that allows users to generate images from a series of text prompts. It uses free diffusion models such as Stable Diffusion as the base model for its image capabilities combined with other tools such as ControlNet and LCM low-rank adaptation, with each tool being represented by a node in the program.

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Wikipedia

ODVA (company)

ODVA, Inc. (formerly Open DeviceNet Vendors Association, Inc.) was founded in 1995 and is a global trade and standard development organization whose members are suppliers of devices for industrial automation applications. To qualify for membership in ODVA, applicants must be an entity that makes and sells products using ODVA technologies. ODVA technologies include the Common Industrial Protocol or "CIP" - ODVA's media-independent, object-oriented protocol - along with ODVA's network adaptations of CIP - EtherNet/IP, DeviceNet, ControlNet, and CompoNet. ODVA has more than 15 technical working groups, overseen by its Technical Review Board, which develop and enhance ODVA's implementation specifications for its technologies. These specifications define how a product shall be designed in accordance with the specifications. ODVA maintains a conformance testing practice to validate that products designed using ODVA technologies comply with the specifications and interoperate in multivendor systems. ODVA also provides other services to its members to promote the adoption of ODVA technologies by industry. ODVA is a US 501(c)6 corporation incorporated in the state of Wisconsin. Its headquarters are in Ann Arbor, Michigan U.S. It also has conformance test service providers in North America, China, Germany, and Japan.

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Wikipedia

Common Industrial Protocol

The Common Industrial Protocol (CIP) is an industrial protocol for industrial automation applications. It is supported by ODVA. Previously known as Control and Information Protocol, CIP encompasses a comprehensive suite of messages and services for the collection of manufacturing automation applications – control, safety, synchronization, motion, configuration and information. It allows users to integrate these manufacturing applications with enterprise-level Ethernet networks and the Internet. It is supported by hundreds of vendors around the world, and is media-independent. CIP provides a unified communication architecture throughout the manufacturing enterprise. It is used in EtherNet/IP, DeviceNet, CompoNet and ControlNet. ODVA is the organization that supports network technologies built on the Common Industrial Protocol (CIP). These also currently include application extensions to CIP: CIP Safety, CIP Motion and CIP Sync.

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TOPIC OF THE DAY

Greenwood / Black Wall Street

Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.

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TRIVIA QUESTION OF THE DAY

Who became the first Black woman to travel into space?

Mae Jemison, aboard Space Shuttle Endeavour in 1992.