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Newsletter Issue # 33

Real Time Automation's - Best Darn Newsletter 

The Dr. No of Automation Complexity
The Buetooth Low-Energy (BLE) Standard
Fun Facts and Trivia

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October 19, 2016
October 19, 2016
EtherNet/IP and TCP/IP
October 4, 2016
OPC – Are its days numbered?
September 30, 2016
September 23, 2016
The Chicken-or-Egg Problem around OPC UA Security
September 13, 2016
When NOT to Use Modbus



Practical tips and information for young engineers. This issue, featuring:

- A Tip of the Hat to Systems Integrators; Cutting Through the Noise



The Dr. No of Automation Complexity

A Column of personal opinion by John Rinaldi, Founder and Owner of Real Time Automation.

It was all just so mysterious: the blindfold, the hour of driving in circles to disorient me. Where are we going? Hans said it was a secret location, but this was pretty strange!

They removed my blindfold as we pulled into a nondescript building in a part of town that looked different from anything I’d ever seen in my global travels. Hans said that he built the facility specifically for automation product testing.

Very curious and very strange - but that describes Hans. He’s an odd sort. Tall and lanky with piercing eyes and a pug nose. And even more astounding for a European, he hates soccer. He’s always been the secretive sort, but now he’s really starting to carry it to extremes. I’ve known him for quite a few years otherwise I would have been a lot more nervous.

We started the tour. It’s not a large facility but Hans has the best equipment. He can run any kind of product test that you can imagine. He’s a brilliant engineer who loves criticizing the work of others. I think it might just be a cruel streak in his personality.

Finally, we arrived at The Room. The place I always suspected might exist but never had any proof. A few months ago in New York City, Hans had a few too many rum and cokes and told me that not only did The Room exist, but some of the largest automation product developers use it for product testing. And what’s more, I could see The Room!

Actually it’s a fairly non-descript room, with no special equipment apparent. Just a desk where a control engineer can interact with the user interface of some piece of automation equipment.

The Puzzlement Scale
The real guts of the system is the camera software that monitors the user’s face as he attempts to configure and use the device under test. Hans explained that his proprietary software very accurately determines the functionality and flexibility of an automation device by reading the puzzlement on the user’s face. He grades the device functionality and flexibility on a scale of 0-5. Zero means it’s understandable. At two, there is a modicum of understanding. At four, the device is deemed “highly functional” as the degree of puzzlement is high. And at five, the best score in The Room, we have complete user confusion.

Hans indicated that he regards anything less than 3.5 as a failure. The automation device is then rejected and returned to the design team to add more options, functionality, checkboxes and increased product scope. Automation devices not reaching a sufficient level of puzzlement don’t have the flexibility and functionality to meet the requirements for a sufficiently wide range of product applications. Hans argues there is a direct correlation between the features, options and complexity of a product and the number of units that could be sold. As far as he knows, he is the only one to provide this kind of puzzlement test, he told me proudly.

The Real Product Cost: Deployment Time
I’ve always suspected this approach existed, given the complexity I’ve seen in the automation market. Now I knew it and had the evidence to back up my constant claim that automation products are just too darn complex.

Hans doesn’t believe that, of course. He believes that with more complexity, you can meet the requirements of more applications, sell more product and make more money. I argued that complexity is a killer in the marketplace. That the real product cost is deployment time, and all that complexity vastly increases the deployment time and true product cost.

Our argument went far into the night. His stubbornness versus my logic. It ended when he walked out and slammed the door on me. Back home to RTA I went where, thankfully, simplicity reigns!

And there are no blindfolds.




- John




Christmas Trivia

·  What kind of bird has "gone away" in the song Winter Wonderland?

·  Who tells you she's in town by tap, tap tappin' on your windowpane?

·  What is Frosty's nose made of?

·  Who kept time with the Little Drummer Boy?

· What one reindeer is never mentioned in "The Night Before Christmas?"


Answers located on bottom of page.


The Bluetooth Low-Energy (BLE) Standard

Bluetooth is one of those technologies that just keeps slowly creeping into our industrial automation applications. A lot of that is because it’s being forced on us. As PC manufacturers continue their crusade to make personal computers less expensive than a cup of coffee, they’ve eliminated all the serial connections we’ve used for the last 30 years. Bluetooth is now one way we can connect to devices that in the past were connected with good old RS232, RS485 or USB cables.

There is an interesting history to the name Bluetooth though I don’t know the veracity of the story. Bluetooth is a Danish technology, and once upon a time, in the 10th century there was a Danish king named Harald "Blåtand" Gormsson. Harlad was the son of “King Gorm the Old” – though I doubt that any of his subjects called him that to his face. Harald became known as King Harald Bluetooth. Though the actual reason is probably lost to history, historians surmise that the derivation of the moniker is from a conspicuous bad tooth that probably appeared "blue,” which at that time was commonly used to mean dark (Stay tuned for the story of old King EtherNet/IP in our next issue).

The Bluetooth standard was published in 1999 and it’s now part of the 802.15 standard (802.15.1) along with other wireless communication technologies like Zigbee (802.15.4). Like many other technologies we use, there have been a few different releases:

 Version 1.x

The first series of useable releases starting in February 2001.

Version 2

In 2004 this was the first version to become widely disseminated. Known as EDR (Enhanced Data Rate) Bluetooth, it increased throughput to 3.0 Mbps. EDR made phone headsets and external microphones for cellphones viable.

Version 3

An even faster version that increased the data rate to over 10 Mbps in 2009. This version is sometimes known as Bluetooth HS for High Speed Bluetooth.

Version 4

In 2009, the Bluetooth Low Energy (BLE) standard, sometimes called Wibree, was released. This version provided mechanisms for battery powered sensors to use Bluetooth in a way that conserves battery life but reduced range and signal strength.

The BLE standard is of growing importance to us in industrial automation. We can expect to see more and more field-level Bluetooth pressure, temperature and vibration sensors as vendors move to BLE to reduce wiring costs. Sensor applications that require sporadic monitoring (500 msec or more) are good candidates for BLE, such as tank level, temperature and pressure monitoring.

The BLE Radio (physical layer) uses 40 channels in the unlicensed 2.4 Ghz radio band. It is spec’d for 100 m and 2.1 Mbps, although you won’t see that in practice. 2.4 Ghz is also the frequency band used in car alarms, cordless phones, Zigbee and WiFi devices. BLE Radios avoid disruption from these other 2.4 Ghz devices using Frequency Hopping Spread Spectrum (FHSS) to hop from frequency to frequency. (An interesting side note to FHSS is that it was an invention of American actress and WWII pin up girl, Hedy Lamarr. You’ll want to read that story. Apparently her mind was as incredibly well developed as her figure.

Like Ethernet devices, every BLE device can be identified by its unique 48 bit ID. Just like Ethernet, this ID is composed of 24 bits identifying the device manufacturer and 24 bits uniquely identifying that manufacturer’s device.

Advertising Their Presence
Advertising is one of the more interesting and unique aspects of BLE. BLE devices send unsolicited “advertising” packets out to announce their presence to interested BLE “observer” devices. The advertising packets are sent infrequently as BLE devices sleep the majority of the time. They wake up periodically (typically once a second), advertise their presence to any observers, and then return to energy-conserving sleep mode.

There are three specific frequencies in the 2.4 Ghz band that all BLE devices use for advertising: one at the lower end of the band; one at the higher end; and one near the middle. A BLE device transmits its advertising packet on all three frequencies in the hope that one of them is clear of other traffic. Observers monitor all three and ignore the remaining 37 frequencies. The rate that a device transmits its advertising packet is application-dependent, but usually not less than a few hundred milliseconds. At faster rates, a WiFi application makes much more sense.

Included in the advertising packet is the device hardware address (think Ethernet MAC), the vendor ID, the product code and data. Observers can simply listen in and receive data from nearby transmitters or they can optionally connect to the device and perform traditional Master/Slave kinds of communications.

The advertising payload varies from a minimum of 6 bytes to a maximum of 37 bytes where each data group within the payload consists of a length, a data type and the data field. That’s not much data and the Bluetooth designers realized that. When a BLE observer detects a transmitter, it can request an additional response from the advertiser (Scan Response) without forming an energy expensive connection. The Scan response follows the same packet format as the advertising packet and effectively doubles the amount of data that can be received from the device.

If you own something that is part of Apple’s iBeacon standard, you’ve seen an example of BLE advertising. If you’ve been in a retail store where you receive a message welcoming you to the store, you’ve experienced BLE advertising. There are many applications like this.

The iBeacon standard is noteworthy in that the BLE end devices don’t support connections in these systems. They are designed only to be advertisers. Supporting connection mode is optional for BLE devices. Some, like the pressure transducers from Transducers Direct, accept connections, while iBeacon devices won’t.

Tradeoff between Power Consumption and Latency
A critical factor in deploying a Bluetooth system is understanding the tradeoff between power consumption and latency. Every transmission consumes power. The less advertising packets transmitted, the longer the battery life of the sensor. Longer intervals provide longer life, but if the process changes faster than the advertising rate, you miss important data. More transmissions and you reduce battery life. Applications must compromise between battery life and data availability. Users can optionally configure the advertising packet rate of a BLE device.

Don’t make the mistake of thinking that Bluetooth competes with WiFi. That’s just not the case, especially in industrial automation applications. Bluetooth is much slower than WiFi, simpler to configure and good for ad-hoc networks. WiFi is superior for creating larger, higher bandwidth networks over longer distances.

There is a lot more to BLE than I’ve covered in this short article. For more information, a good book on the subject is “Getting Started with Bluetooth Low Energy: Tools and Techniques for Low-Power Networking 1st Edition” by Kevin Townsend.









Fun Facts

·Snow is not white! Technically it is transparent and colorless.

·Although it is the coldest time of the year, Earth is closest to the sun during the winter. The tilt of the axis accounts for weather changes, not proximity to the sun.

·A single snowstorm can drop 39 million tons of snow.

·A snowstorm can only be classified as a blizzard when visibility is impaired for at least quarter mile, winds are 35 miles per hour or more, and the storm lasts for 3 or more hours.




  Trivia Answers: Bluebird; Suzy Snowflake; A button; The ox and the lamb; Rudolph

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