Phil gcfnvvz

'mb' Moshe Barazani: According to the DS303-1 and the Bosch protocol and ISO 11898, the 1Mbit should be supported for bus length of 30meters. Practically we could reach not more than 10meters. This also stands with some notes that I could locate on the web.

Does anyone have any experience to share in such architecture? Did you use “Repeaters” to extend the bus length? Any suggestion in how can a bus be lengthen to 30meters? Any idea what were the different standrad calculations when allowing 30-40 meters?

'oe:' Did you have done any calculations of your overall signal propagation, e.g. adding all relevant delay times transceiver - opto coupler - cable - opto coupler - transceiver ??

As you already said, having all bad components, you will not reach 30m, in the worst case your calculation will end up with a length of minus some meters.

Repeaters will not extend cable length when you stay with 1Mbit/s. They will add additional delay.

'sc' Steve Corrigan: A 30 meter bus should not be a problem with a 1 Mbps signaling rate as long as the cable is at the very least 120ohm CAT 5 twisted-pair cable. Shielded is even better. 5ns per meter propagation delay is typical for this cable. The down and back max prop delay is then 400ns. Then, if you add a 150ns total loop delay for a sending transceiver and another 150ns for the most distant receiving transceiver (in this case HVD251s), then the total prop delay from controller to controller is now around 700ns. Easily enough time for a correct sampling point. I have operated at 1Mbps on 40m without any problems at all. This is, by the way, the maximum bus length specified by ISO 11898 (1993).

Problems you may be having

40m at 1Mbps on a standard bus is no trick at all, so something is not electrically correct with your bus arrangement. This is how your bus should be set up for high-speed operation.

'sc:' Stubs too close together increase the capacitive effects of each – they become a lump sum and damp the effective signaling rate. What isolators are you using? If they're optos you may want to switch to another part like ADI's ADuM1100.

'ob' Oliver Betz: is it a must to use isolation, or to use a (maybe specific) optocoupler? TI's parts are much faster, consume less power and cost less than fast optocouplers.

'mb:' taking the worst case scenario according to the manufacturer you might end up with cable with minus length. The problem is that you cannot get the typical values of the delay and not even some statistics of “how many components might get to the max delay out of 1000”

'ob:' with fast couplers and transceivers I see no problem to make a 100% design. ADuM1100 has typ. 10.5 and max. 18ns prop. delay. HCPLx710 typ. 20ns, max. 40ns. Two times transceiver delay (each 120ns..175ns). Still enough room for several meters of cable. Regarding the probability: comparing the “worst case” and the “typical” values gives an idea about the distribution. A rectangular distribution would be a rather pessimistic but still acceptable assumption. After all, I wonder in which case there could be a real need for galvanic isolation of such a small bus - different, distant power sources?

AFAIK galvanic isolation suppresses only low frequency noise, RF can be filtered better and cheaper. Oliver

Heikki Saha, explains propagation delay, 2013-10-18: Propagation delay consists of:

Some example values:

⇒ Basic implementation without isolation and logic, we get:

ROCHESTER, Minn. (KTTC) – Based in Rochester, Minnesota, KTTC (NBC 10) is the market-leading, award-winning, NBC-affiliated, local television station serving southeast Minnesota and northeast Iowa in the Nielsen designated Rochester-Austin-Mason City television market. KTTC also operates the market’s FOX affiliate, KXLT-TV FOX 47 (owned by SagamoreHill Broadcasting), through a shared services agreement.

KTTC News produces 32 hours of local news broadcasts each week, including a daily one-hour primetime newscast on FOX 47. In addition, NBC 10.2 is home to Rochester’s CW network, and we also have our multicast networks of 10.3 H&I, 10.4 CourtTV, and 10.5 JusticeTV. KXLT also provides 47.2 MeTV, 47.3 LAFF, 47.4 CourtTV Mystery, 47.5 Quest, and 47.6 GRIT.

Whether it’s for our viewers or our advertising partners, our operations cast quite a large net over the market.

Our Workplace

At KTTC, you’ll find a professional culture where the sharing of ideas is not just OK, it’s encouraged! We love to work hard, but we like to work smart even more. Whether you’re a journalist, a production or marketing professional, a sales account manager, or engineer, every team member in every department has their own job to do, so we hire great professionals and give them the tools and framework to excel at their individual craft. Getting better at what we do each day is a daily mantra. No matter what your individual career goals may be, our management team strives to help you achieve those within the framework of our team and station goals. We also offer paid internships.

Take a station tour!

Our Approach to Journalism

KTTC News believes journalists hold an important role in a democratic society. Here at KTTC, we are accurate and fair. We hold the powerful accountable while giving a voice to the voiceless. We gather news and information and present it, assisting people in making important decisions about their lives. We are curious but objective, providing facts, not our opinions. The responsibility is great, the reward is personal. We are courageous as the messenger is not always welcome, the message not always what one wants to hear. The importance is not how we say it, but that we say it. And we get it right. The First Amendment protects us to do nothing less.

With KTTC News’ long-standing tradition of market-leading news and weather coverage, the station has been honored with many Regional Upper Midwest Emmy Awards, Eric Sevareid Awards, and recognitions and awards from the Minnesota Broadcasters Association and Associated Press.

Winning the day is not just something we do; it is who we are.

Our History

KTTC was the first television station in southern Minnesota to sign on the air in July 1953, known first as KROC-TV as a sister station to KROC Radio. In 1976, Quincy Newspapers Inc., now known as Quincy

Media Inc., purchased the station from Southern Minnesota Broadcasting and changed the call letters to KTTC, meaning “Total Tri-State Coverage,” referencing the station’s broad coverage area ranging from southeastern Minnesota to northern Iowa to parts of western Wisconsin. Even now, KTTC’s significant viewership extends beyond Nielsen’s defined Rochester designated market area to the north and east.

Announced in January 2021, Quincy Media and KTTC have been acquired by Gray Television, with the close of the sale in 2021. KTTC will be a part of Gray’s media portfolio serving 102 television markets around the country, 77 of which include the No. 1 rated station in the market.

Our Community Involvement

KTTC prides itself on a very active role in our community. KTTC has raised tens of millions of dollars over the years for local cancer research as it produces the annual KTTC Eagles Cancer Telethon, currently in its 67th consecutive year and holding the distinction of being the longest running locally produced telethon in the United States.

In addition to supporting literally dozens of area nonprofits in various ways, KTTC also conducts the annual KTTC Toy Drive for Christmas Anonymous, annually supports the United Way of Olmsted County through an employee giving campaign, and partners in the Empty Bowls Fundraiser for the Channel One Food Bank serving 14 counties in our viewing area.

Why Live in Rochester, MN?

Mayo Clinic

KTTC is based in northwest Rochester, MN, affectionately known as the “Med City” and home to around 120,000 residents and rapidly growing. Rochester is best known as the home to the world-renowned Mayo Clinic and is consistently rated as one of the best cities to live in the United States. With Mayo as the base, the Destination Medical Center has become a regional draw for many companies in the medical field and a welcoming destination for 3 million+ visitors each year. Because of those additional visitors, residents also get to enjoy a wide array of hotels, restaurants, and bars that may not otherwise be in a city of this size.

Festivals & Events

Rochester’s culture of caring, spirit of innovation, and fascinating history makes it an interesting place to call home. The Rochester Downtown Alliance plans and coordinates all sorts of great festivals and events, many that KTTC has a long history of sponsoring. Summers are highlighted by the weekly “Thursday’s Downtown,” a live music and food street fest, and the annual wintertime event, “Social ICE,” where Rochester’s downtown is lit up with ice sculptures, DJ’s, and Ice Bars.

Dining, Shopping & Recreation

Enjoy Rochester’s scenic beauty at one of the city’s 100 parks, or visit only-in-Rochester restaurants, breweries, shops, year-round farmer’s market, and attractions to experience the true flavors of our vibrant upper Midwest city. We truly get to enjoy all four seasons of the year with many golf, hiking, and boating options in our mild summers and downhill and cross-country skiing, skating, and sledding in our snowy winters.

Road Trips

The Twin Cities

Perhaps you’d like to take advantage of the unique perk of working in the Rochester market and make the one-hour drive up Highway 52 to the Twin Cities of St. Paul and Minneapolis, the 15th largest television market in the country. There you can also enjoy major metropolitan amenities, museums, concerts, NFL Vikings, MLB Twins, NHL Wild, and NBA Timberwolves games. MSP, the region’s main airport and Delta Airlines hub, is consistently rated as one of the top airports in the country offering many direct and affordable flights.

Other destinations for a day trip or weekend getaway include:

Bloomington, MN – 1 hour

Brooklyn Park, MN – 1 ½ hours

Duluth, MN – 3 hours

Des Moines, IA – 3 hours

1. Bitcoin Bitcoin is possibly the best-known cryptocurrency, and is now into its 13th year having launched in 2009
2. Ethereum
3. Solana
4. Polkadot
5. Binance Coin