Factory automation: four problem-solving technologies

There is a new industrial revolution. It’s combining advancements in machines and controls with advancements in computing and communications from the Internet revolution. Today’s technology is being applied in ways not even thought of even 10 years ago to solve problems and increase industrial productivity.

That’s where the challenge of mixing new and existing technologies in an industrial environment comes in. Here are four problem-solving technologies for industrial networking.

1. Fiber for distance and EMI/RFI immunity.
Fiber optic cable is often the preferred cable choice in industrial environments because it can cover very long distances and offers immunity to electrical interference.

Fiber doesn’t have the 100-meter distance limitation of twisted pair copper, so it can support distances from 300 meters to 40 kilometers, or more, depending on the style of cable, wavelength, and network.

Fiber also provides extremely reliable data transmission. It’s completely immune to many environmental factors that affect copper cable. The fiber is made of glass, which is an insulator, so no electric current can flow through. It is not affected by electromagnetic interference and radio-frequency interference (EMI/RFI), crosstalk, impedance problems, and more. You can run fiber next to industrial equipment without worry.

2. A ring topology for redundancy.
Although Ethernet is usually thought of as having a star topology, it’s possible to build an Ethernet network as a ring. This is often used in applications where it may be difficult to run fiber in a star formation from a central switch, such as in industrial or even traffic signal applications.

One industrial networking scenario involves connecting industrial devices, such as computer numeric controlled (CNC) machines, to hardened Ethernet switches. The switches are set up in a ring topology for maximum reliability with a failover time of less than 30 ms, which is virtually instantaneous. The ring has the advantage of providing a redundant pathway if a link goes down. If one part of the ring fails, traffic will automatically reverse direction.

3. Machine vision and USB 3.0.
Machine vision is an image-based automatic inspection technology that is now an indispensable tool for quality assurance, sorting, and material handling in every industry, including electronics, food processing, pharmaceuticals, packaging, automotive, etc. Machine vision technology incorporates cameras, PCs, software, and other hardware to automatically take pictures and inspect materials as they pass along an assembly line.

Machine vision is an economical way to make sure sub-spec product is rejected. It can be used to inspect for geometry, placement, packaging, labeling, seal integrity, finish, color, pattern, bar code, and almost any other parameter you can think of.

USB 3.0 greatly enhances machine vision systems. Because of USB 3.0’s 5-Gbps throughput, ten times more than USB 2.0, it eliminates problems of stability and low latency for image transmission and camera control. USB 3.0 enables the transmission of higher-resolution, higher-frame video with no loss of quality.

4. Industrial serial connections.
Industrial control is a designation for the devices that interface with machinery such as packaging machines, generators, lathes, and even scales. Although most of today’s IT runs on Ethernet, industrial devices often use an RS-232, RS-485, or RS-422 serial interface. To capitalize on the investment in the industrial equipment and machinery, interface converters and line drivers can be used to provide the link between older RS-232/422/485 equipment connections and newer USB and Ethernet networks.

RS-232 transmits data at speeds up to 115 kbps and over distances up to 50 feet, although higher distances can be achieved by using low-capacitance cable. Both sync and async binary data transmission fall under RS-232. Although the original RS-232 connector is DB25, DB9 and RJ-45 connectors are now more common. Also, industrial devices often use a terminal block instead of a connector for the RS-232 interface. RS-232 is somewhat restricted as an industrial interface because of its restricted range and because it only supports point-to-point links.

For a far more detailed study of industrial communications, see the white paper: Elements of an RS-422/RS-485 System.

The importance of properly cleaning fiber during termination – Part 3

This is part three of a three part series on fiber cleaning. For part two, click here.

From the August, 2014 Issue of Cabling Installation & Maintenance Magazine
By Sean Sheedy

Unless you are working in the tropics, never select a water-based fiber cleaner. It is very slow to dry and will freeze in cold weather.

One excellent characteristic of IPA is its ability to dissipate static. With a static charge, particulate will bind to surfaces surprisingly aggressively. For example, a large 500-micron (μ) particulate takes twice the force of gravity (2 G’s) of “scrubbing” (mechanical action) to remove. But a 5-μ flake of solid residue takes 20,000 G’s to break loose from the intermolecular grip the particulate has on the substrate. How do you get 20,000 G’s of scrubbing force inside an LC connector? You don’t. So solvents help solve the problem by neutralizing the static charge.

In the past decade there have been at least two studies looking at static on endfaces. iNEMI’s results were presented in “Accumulation of Particles Near the Core During Repetitive Fiber Connector Matings and Dematings,” at NFOEC in 2007. And during the development of the IPC-8497-1 standard, 18 researchers worked on the problem of static. Their findings were presented in “Cleaning Methods and Contamination Assessment of Optical Assembly,” at NFOEC in 2006. This research clearly observed that wiping an endface with a dry wipe did not dissipate the static on the endface, and indeed may have added a triboelectric charge to the endface, which made the endface even more prone to attracting particulate. This problem was eliminated with a wet-dry cleaning process, in which a cleaning fluid was used to dissipate the static, and then a dry wipe was used to polish away any residual fluids. This is an excellent procedure and should be used by everyone in the fiber industry.

The importance of properly cleaning fiber during termination – Part 2

This is part two of a three part series on fiber cleaning. For part one, click here.

From the August, 2014 Issue of Cabling Installation & Maintenance Magazine
By Sean Sheedy

Amazingly, cleaning was a problem in the earliest fiber installations, more than 40 years ago, and is still the primary operational problem in the industry today. Are we all a bit slow on the uptake here? Companies need to refocus their efforts to properly clean every endface, both sides, every time they touch their connectors.

It is absolutely essential the bare fiber be perfectly clean before inserting into a ferrule during connectorization. Here the operator is preparing to clean with a high-quality lint-free wipe that does not contain any glues or cellulose. The cleaning fluid evaporates quickly and the canister cannot be refilled, which ensures the cleaning fluid will remain pure and uncontaminated.

Cleaning tools: Good, bad, ugly
Let’s take a look at the tools we give our techs. Usually it is a box of cellulose wipes and a pump bottle of isopropyl alcohol. What’s wrong with these time-proven choices? Almost everything.

The lint-free wipe needs to be truly lint-free. Many wipes are made of cellulose, held together with glue (called “binders” in the paper trade). Cellulose fibers are weak and shred easily. The glues that hold the paper together are dissolved by liquids such as water and alcohol, so glue often leaches out onto fiber surfaces. So while you may have removed that pesky fingerprint from the endface, now you have left other residues on the endface that may be just as much of a problem as the original dirt.

A related issue develops when companies buy their techs high-quality wipes, but because these wipes are more expensive the operators don’t dispose of them after each use. As they said in Apollo 13, “Houston, we have a problem.” Wipes should never be re-used, because contamination migrates. So in this situation, the techs simply are moving the dirt from one fiber to another.

The importance of properly cleaning fiber during termination – Part 1

From the August, 2014 Issue of Cabling Installation & Maintenance Magazine
By Sean Sheedy

Using a medium only slightly larger than a human hair, fiber-optic communication has transformed our world. Not only have fiber-optic communications eliminated the vast majority of previous network limitations, but this technology also has expanded the capabilities of networks far beyond previous expectations. Today’s world of mobile communications and video downloads is a direct result of the rapid and affordable deployment of powerful, reliable fiber-optic networks. If anyone ever develops a roster of “disruptive technologies,” (as Joseph L. Bower and Clayton M. Christensen did in their 1995 Harvard Business Review article titled “Disruptive Technologies: Catching the Wave,”), then fiber optics should be number one on that list.

Fragile signals
Amazingly, the signal carried by the fiber is astoundingly fragile and becoming more so. After more than 20 years in the industry, I can confirm there really are only two threats to a fiber signal: too much bending and too much dirt. At a BICSI Conference in 2008, JDSU stated, “Contamination is the number-one reason for troubleshooting optical networks.” A major telecom company, rolling out a new fiber-to-the-home service, found that 16 percent of all their connectors on their expensive new network were sufficiently contaminated to cause performance problems. Cleaning is not merely important; it is critical to the long-term reliability of any network, and at the heart of the profitability of a successful fiber deployment. Field techs must be taught, and must be provided the right tools, to clean every endface, both sides, every time they are installed, tested or reconfigured.

The two biggest causes of fiber light loss and how to fix them

By Fluke Networks

Fiber optic cabling carries pulses of light between transmitters and receivers. These pulses represent the data being sent across the cable. In order for the data to be transmitted successfully, the light must arrive at the far end of the cable with enough power to be measured. Light loss between the ends of a fiber link comes from multiple sources, such as the attenuation of the fiber itself, fusion splices, macro bends, and loss through adapter couplings where end-faces meet.

Among key sources of loss that can bring a fiber network down, dirty and damaged end-faces are the most underestimated threat. Dirty end-faces are a leading cause of fiber link failure for both installers and private network owners. Contaminated end-faces were the cause of fiber links failing 85% of the time. It’s easy to prevent, but there continues to be a lack of appreciation for this crucial issue and lots of misinformation about proper techniques.

There are two types of problems that will cause loss as light leaves one end-face and enters another inside an adapter: contamination and damage.

Dig up the dirt on your endfaces with this Visual Inspection Probe.

Contamination

Contamination comes in many forms, from dust to oils to buffer gel. Simply touching the ferrule will immediately deposit an unacceptable amount of body oil on the end-face. Dust and small static-charged particles float through the air and can land on any exposed termination. This can be especially true in facilities undergoing construction or renovation. In new installations, buffer gel and pulling lube can easily find its way onto an end-face.