Why use RS232 to RS485 / RS422 converters?

Most new consumer electronics comes with an USB, Firewire or other high-speed communication port, however a lot of industrial and commercial equipment, both old and new, comes with an RS485 or RS422 communication port. So in order to transfer data from a RS232 or RS485 device to for example a computer engineers need an RS232 to RS485 or RS232 to RS422 converter. The reason is that the serial RS232 / RS485 / RS422 protocol is, even its old, a very reliable, stable and solid communication protocol, which can easily be implemented with existing industrial equipment.

So what is RS485?

RS485, also known as TIA/EIA-485 or RS-485 is a standard protocol defining the electrical characteristics of drivers and receivers for use in balanced RS485 digital multipoint systems. Even RS485 is not commonly as popular as RS232 it is extremely useful in industrial and commercial RS485 environments. RS485 is an often used interface in data acquisition and control applications where multiple nodes communicate with each other.

The advantage of RS485 over RS232 is that RS485 can transfer data over longer distances, up to 4000 feet, and have up to 32 nodes per single network, whereas R232 cannot be used for multi-point networks. RS485 uses two wires for communication, one for transmitting and one for receiving RS485 data, which is referred to as half-duplex communication. The common-mode voltage range for RS485 is -7V to +12V.

Usually RS485 is the preferred way to establish multi-point networks. This is a method to connect multiple RS485 devices with each other over a RS485 two-wire network. This is because RS232 to RS485 converters can easily be addressed either by software or by DIN-switched on the particular unit.

And what is RS422?

Most RS232 to RS422 adapters are 4-wire, full-duplex, differential protocol with multi-drop capabilities and has a recommended distance limit of 3600ft. ANSI/TIA/EIA-422-B is the American national standard for RS422. RS422 is for data transmission, using balanced or differential RS422 signaling, with non-reversible, point to point or multi-drop, and is terminated only on the end of the line opposite the RS422 transmitter. In contrast to EIA-485 (which is multi-point instead of multi-drop), EIA-422/V.11 does not allow multiple RS422 drivers but only multiple receivers. Due to loading limitations one of the best uses of RS422 might be in point-to-point communications, such as RS232 extension cords.

RS422 is however very effective as a line extender, for example to extend a RS232 wire. You do this by converting the RS232 signal to RS422 and then back to RS232. This way you can extend the RS232 signal up to 3600 feet. RS422 is also often used in older RS422 devices such as older PLC’s and terminal equipment.

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When I keyed in the words exchange support to read a little more about the various options available in the market, two warning statements or rather two sets of warning statements struck me as rather interesting. The first strongly cautioned that one should stay away from the least expensive contractor following the axiom that paying for peanuts gets you monkeys! Interesting advice as normally lower quotes tend to get ones attention.

The second bit of warning/advice was that in the event that before one actually bought Microsoft exchange server software one should get extensive training. The MS server as I understand is a very useful tool in that it enhances communication and protects and improves communication, a vital business tool. MS Exchange can also be very effective in stopping spam. It also has the ability to grow with the business. What I found odd was that normally, one looks at training and tutorials post acquisition of a product. In the case of the MS exchange server, it seems the opposite.

In order to better understand the product there are several options available to users. First, there are internet tutorials on MS Exchange that would benefit, in my mind the more techs savvy amongst us. Alternatively, one could look at joining a Microsoft Exchange ASP and software certification and training course. The point that is really being driven home here with regard to the MS exchange server really is that this application is as good as the mind that manages it. Therefore, all those employees that would be using the MS server should enter in depth tutorials to manage the same

Let’s go back to the first warning that I mentioned that was with regard to an externally hosted exchange server. I believe that there are many vendors in the business for this service and I am told that their service features are fairly standard. At the end of the day for a business what really matters is the quality of the customer service and the smooth functioning of the server, i.e. the up time.

For a business that chooses to go for an externally hosted exchange, you have to be thorough in your vendor selection. Check the exchange server support helpline turnaround time whether it is by e-mail or by return phone calls. Also, another element is the quality of the exchange support. Does it make any sense to you or your business or is it only adding to the clutter? Try chatting online with exchange server staff, see if their tone and quality of advice is something that works for you. The MS exchange is a vital life line of your business, you must choose a MS exchange support vendor who comes well recommended by your peers. Manufacturer website and Industry magazines also provide useful rating services that could prove helpful in your selection of a MS exchange server. Use the free trial periods to the fullest before finalizing your support vendor.

The second warning, piece of advice that I mentioned earlier is something that I am going to pass up. Really, if I have to invest this kind of time and money on training, I really am going to be in trouble. I will get my own exchange but I will call in the experts to manage it for me. I need full time exchange server support from what I have understood about the product and who better than a qualified tech support company. They can look after the installation of the exchange server; troubleshoot as and when required as well as look at any updates and fixes.

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What’s the first and possibly the biggest tip to saving on portable printer-scanner combinations? Specialization, specialization, specialization! The more types of papers, size differences, and image qualities a printer and scanner can handle, the more expensive it will be, as a general rule. But why would you pay for something so versatile if you’re not going to be making full use of that flexibility? Most people only need to print and scan particular types of things while on the move. For more demanding things, well, that’s why you have a non-portable office printer and scanner, right? Think about the kinds of things you’d really need to scan and print when away from your office. Chances are there’s not a lot of different types of things in that list. Then, narrow your choices down to the printer and scanner combinations that only handle those necessities and nothing more. The more needless functions you cut out of your dream machine, the more you can save by getting a specialized-function machine that still does every little thing you need it to do. This goes for more than just scanner input and printer output, too. Savings can also be had when looking at computer compatibility. If you use a PC laptop, you don’t really need a portable scanner-printer that specifically flaunts cross-compatibility with PCs and Macs, now do you? Buy only what you need to spend only what you have to.

Then there’s buying used. While you may associate that with the acquisition of badly-handled products that are unfit for projecting a proper business-like atmosphere, this doesn’t have to be true if you do your homework. Let go of any lingering bias you may have against buying anything that isn’t shrink-wrapped and sold at retail price; this is the best possible time for getting used bargains! Businesses are closing down and businessmen are selling off their printer-scanner machines at rock-bottom prices in hopes of just getting anything back. Since these kinds of products are generally used for business purposes, you can usually rely on them being in good quality even despite being used. A businessman would no more mistreat his portable scanner and printer than a fisherman would snap his fishing rod in two, and you can reap the benefits of that gentle care. If you buy used online, then make sure to pay attention to the seller quality aspects that are provided by most sites. Things like star ratings, past customer reviews and so on will help you know for sure if a seller is as good as his word or not. Also pay close attention to shipping fees, since some less than scrupulous sellers will attempt to attract people by posting unrealistically low prices, and then sneaking in excessively high shipping in smaller, overlooked text. Don’t fall for it, it’s one of the oldest tricks in the book of internet scams.

And that’s pretty much it, as far as big saving tips go. Surprised? While these two aspects of shopping for a printer and scanner aren’t so hard to learn, they’re very effective. While there are other minor ways to save, they’re dwarfed by the sheer potential savings involved in buying used specialty equipment. Always remember to buy just what you need, and to not pay solely for the fancy packaging, and you’ll get equipment as good as that of any of your coworkers for half what they spent.

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There are a number of considerations to take into account when selecting the best fit for your company and care should be taken before signing up with the first “quick and easy” solution, no matter how attractive the offer of a “free site within hours” may be. As with all things in life, you have choices to make but be aware that the choice you make now may haunt you for a long time to come. It will pay dividends if you spend some time doing your homework.

Firstly, as a restaurateur, you should know that ordering food is very different from ordering a book. When you buy a book online, does it really matter if the supplier is temporarily out of stock and that you have to wait an extra day? Do you expect to customize the book? How about delivery zones, kitchen capacity, menus by time of day or day of week, specials, meal deals, half and half pizzas, group orders? The first lesson is that a “shopping basket” does not suit the needs of the restaurant industry, period. There are, unfortunately, a lot of service providers who have taken the simple shopping basket and modified it slightly or sometimes not at all and are now offering it as a solution for restaurant online ordering.

So, before leaping into offering online ordering to your customers, try to think of your online store as a the opening of a new “brick and mortar” store – imagine that this store is going to be your flagship store in time to come. It needs to be carefully designed, planned, built and implemented after consideration of your needs rather than thrown into a “one size fits all” template. Going back to the brick and mortar example, if you were opening a new store, would you choose your shop fitter because he offered to fit your shop in a few hours or simply supply you with the tools to do it yourself? Would you buy your tables and counters from the local DIY store? The answer should be easy but yet many restaurant operators (even large chains) opt for an ill fit when it comes to building their presence on the web.

All of the rules that apply to creating a store and enticing customers to order from it apply equally to your presence on the web; so you should be making sure that you do it properly by starting with a solid foundation that you can build on.

Normal common sense rules should come into the process. Make a checklist of what is on offer and research the companies that you are considering using. First and foremost, check that the provider is Payment Card Industry (PCI) compliant and certified. If they are not, you could be fined heavily or lose your merchant account. Always be cautious about a service provider with no telephone number on their website.

Have a look at the service provider’s list of customer’s sites on their website. How user friendly is the system, can you customize an item; are meal deals offered and easy to use? Try a search of the term “powered by ……. (Vendor’s name)” this should bring up a list of all the sites which have online ordering by that provider. Does the provider have any chains of restaurants as customers or are they all single locations – if there are no chains, ask yourself why not? What associations is the provider linked to – endorsement by an association is a vote of confidence. Ask the service provider if you may inspect the facilities where they host the service and store your customer data – if only to make sure that the hosting is not being done from a garage in someone’s home! Check whether they provide 24/7 support and if so ask for the number and try calling it after hours.

The list could go on and on, dealing with issues such as feature sets, functionality, versioning etc. all of which can seem daunting. Don’t be scared to ask questions, remember, there is no such thing as a silly question and you should view entering into a contract with your provider as the beginning of a relationship – make sure it is a relationship that you are comfortable being in.

Above all, remember that restaurant online ordering really does work and can prove to be a very profitable venture if it is done right. However, merely having a website with online ordering is not going to dramatically increase your orders. You will need to market your site, encourage customers to sign up and introduce new customers through promotions and specials, increase customer loyalty through loyalty programs etc. All of these marketing activities are vital to the good health of your new store. So remember, this is not just a website that is “nice to have” – this could be the most profitable store you have ever owned. The choice is yours!

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With the new rules in the Federal Rules of Civil Procedure with regards to E-Discovery, back-up tapes are not only important to the IT Department should a server fail, but are now critical when a company finds itself in the midsts of litigation. Some examples of different types of information which could be required through litigation include:

NIDA (Non Invasive Data Acquisition)
Accounting Information
Corporate E-mail
Intellectual Property Disputes
Insurance Fraud Cases
Corporate Investigations
Corporate Counsel Support
Electronic Records Management
In a recent case, AAB Joint Venture v. United States, 2007 WL 646157 (Fed. Cl. Feb. 28, 2007), the court heard an argument regarding the a period of time (data) for which that data was not available. The defendant claimed that it had provided all e-mails related to the case. However, the court was not persuaded by defendant’s arguments, and agreed that defendant’s overall production of emails had been far from adequate. The court also said that, while cost was an issue for the court to consider in addressing a motion to compel, it was not the only consideration. The court continued with the following statement:

Here, because the Court finds that defendant had a duty to preserve evidence, as set forth below, the Court cannot relieve Defendant of its duty to produce those documents merely because Defendant has chosen a means to preserve the evidence which makes ultimate production of relevant documents expensive. Accordingly, the Court concludes that Defendant has not adequately responded to Plaintiff’s requests for production of electronic documents and that supplementation of its response to Plaintiff’s requests is necessary. IT departments should verify backups are able to be restored and the data is intact. Not many IT departments routinely check the back-up server’s error logs to discover potential problems. Only when a disaster occurs do they realized that the scheduled backups have not been collecting all of the data.

From an IT point of view, this is one of the worst case scenarios they deal with on a daily basis. From a legal point of view, those backup tapes…or lack thereof…are just as damaging. Those tapes represent a snapshot in time for that company which can either help or hurt their litigation.

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There are different classes or types of “Spyware”. These are summarised below.

· Tracking Cookies. Cookies are text files saved by the browser that allow tracking of user activity on a website. Users typically allow cookies as some sites won’t work without them or they are useful in that they store information about personal preferences, IP addresses, login information, user options and date and time stamp of the last time the site was visited. Cookies may also contain any information provided by a user during a particular visit – including any personal information provided in the course of completing forms. Cookies are at the most benign end of the “Spyware” spectrum.

· Adware. This form of “Spyware” is responsible for generating the by now familiar pop-up, pop-under, banner, floating and animated advertising seen whilst surfing the web. Adware typically uses advanced scripting that manipulates the browser by exploiting flaws in Java, ActiveX, the operating system and the browser itself. Adware may collect information for cookies and report information directly to sites on the Internet. On clicking-through ads additional cookies or utilities may be installed silently. Some adware makes changes to browser settings – resetting the homepage for example – or to the user system (including Windows registry changes). Often clicking on ‘No’ or ‘Cancel’ buttons within the advert result in the same code executing as if the user had clicked on ‘Yes’ or ‘OK’. Adware is the greyest area of “Spyware” – some Adware certainly should be considered as malicious ‘malware’.

· Scumware. Scumware modifies the contents of a web page adding hypertext links and alternative text. Scumware can also position competitive ads over the originals. Scumware can also install hidden or background processes and services and should therefore be considered as malware.

· Malware. Originally malware referred to viruses, worms and Trojan horses. The term also applies to the more disruptive forms of “Spyware”. Such programs might enable third parties to take control of microphones and web cams installed on a particular client, make changes to browser and systems settings, launch Web activity even when all browser sessions are shut down, install hidden or background processes and services. Keyloggers fall into this category. Malware is the most damaging of all types of “Spyware” from a risk perspective. It should be noted that this form of “Spyware” is increasingly being spread through Instant Messaging applications.

1.1 Different Variants, Different Risks

The different types of “Spyware” present different risks to enterprises. Cookies raise privacy concerns but are relatively low risk.

Adware can begin to impact heavily on productivity. Orthus are aware of several instances where close to 200 different pieces of Adware were present on a single client degrading performance to the point where the client was unusable. In addition to user productivity, productivity is affected through increased help desk calls and the time spent by help desk staff in cleaning up or re-building infected machines – which in turn further impacts user productivity whilst the infected machines are unavailable.

The risk of data leakage – of both personal and corporate information – is a very real threat with the most malicious type of “Spyware”.

Mitigating the Risk

The main technologies available to mitigate against the risks associated with “Spyware” within the enterprise environment are discussed below.

Mitigation techniques are two-tiered or two-part – at the gateway and at the desktop level.

Desktop Protection

At the desktop or client there are notably three technologies available to mitigate against the risks posed by “Spyware”. These are personal firewalls, dedicated anti-spyware programs, and traditional desktop anti-virus (AV) tools.

AV

In some respects forms of “Spyware” strongly resemble viruses. They are uniquely identifiable, can be detected by scanning the client machine and are sometimes packaged as a set of files that can be removed to clean up the infected system. However many forms of “Spyware” do not reside on disk as persistent files – such as hostile ActiveX and Java applets. The motives, delivery mechanisms and often the removal of “Spyware” is different however from the protocols followed for viruses and worms.

“Spyware” is also different in that there is no one definition agreed on what constitutes “Spyware”. Some programs that might be classed as “Spyware” – such as Microsoft’s Windows Update Notifications – are useful, disclose their tracking capabilities, do not disrupt desktop operation impacting user productivity, and are distributed by responsible companies. “Spyware” therefore needs to be classified and identified by the actions it performs and the level of risk – complicating detection and removal, as the users must be given a choice over what is permitted.

AV vendors – notably Trend Micro, McAfee and Symantec – already have software that is very good at scanning files before they execute. The software also has mature enterprise management suites and the vendors have support teams in place to handle enterprise customers’ needs.

Independent reviews and tests show repeatedly that AV tools are not as good at catching “Spyware” as dedicated anti-spyware programs. Whilst AV tools may detect 99% of viruses this number falls considerably to perhaps 70% – when considering “Spyware” programs.

Using the next releases of desktop AV tools to protect desktops against “Spyware” is extremely attractive to enterprises. There is no need to deploy yet another software agent on every machine within the desktop population, there is no need to monitor yet another ‘console’. AV already incorporates the management features that enterprises require – such as ‘headless operation’ and centralised reporting. Enterprises achieve greater consistency with standardisation on a smaller number of vendors, leading ultimately to cost efficiencies.

Dedicated Anti-Spyware Programs

There is an ever-increasing list of dedicated anti-spyware programs available from vendors including Ad-Aware from LavaSoft which is the most popular product with some 128 million downloads to date. Other notable products include SpyBot Search and Destroy, CounterSpy and Spyware Eliminator. Microsoft has also entered the market with Windows Antispyware following their acquisition of Giant Company Software.

Whilst dedicated anti-spyware programs are more effective today at detecting and removing Spyware than AV products this will change over the forthcoming quarters. Most of the dedicated anti-spyware offerings are available as free downloads aimed at consumers / individual users and not at large enterprises. Site licensing is rarely available for example. Some of the emerging vendors have enterprise offerings on their roadmaps. However these companies are small, lack corporate / financial stability in some cases, and typically do not have the support teams and infrastructure in place to handle large enterprise customers.

Orthus are of the view that many standalone dedicated anti-spyware programs will cease to exist in the relatively near future and the dedicated anti-spyware market will not be significant in years to come as established vendors offer integrated AV/anti-spyware/personal firewall products.

Personal Firewalls

Just as AV tools now include some “Spyware” protection so many of the personal firewalls available offer a level of protection as well. These include McAfee, Check Point and Internet Security Systems (ISS) with the release of Proventia Desktop in March 2005. Sygate is following a similar path to Check Point and ISS.

Personal firewalls are recommended for particularly mobile clients that are regularly taken outside of the corporate perimeter and used to access corporate systems from DSL connections in the home and public WLAN hotspots, where typically direct Internet access is also allowed. They are also recommended for fixed desktop and mobile clients in smaller locations where there is little or no gateway level protection in place and where again direct Internet access is available from those locations.

Gateway Protection

Desktop protection is only half of the story when it comes to “Spyware” protection. Gateway level protection is also available.

Blue Coat offer a range of proxy appliances that, in conjunction with popular URL filtering solutions, offer a strong defence against “Spyware”. “Spyware” often secretly installs via “drive-by” installers, which install “Spyware” in the background without any user interaction. Blue Coat combats this with anti-spyware policy controls that inspect, filter and block web content associated with “Spyware” installation software. This preventive approach is critical when “Spyware” originates from an unknown web site – not yet categorised within URL filtering solutions – and when there is no known signature available to detect the malicious program.

Gateway protection incorporating a strong URL filtering solution is particularly good in preventing programs on infected systems from sending information back to “Spyware” sites, mitigating against the productivity impact of Adware but also the more serious privacy and data leakage concerns associated with more malicious code. URL filtering solutions also offer some protection from infection in the first place by preventing users from visiting known infected sites.

Gateway solutions typically incorporate logging and reporting features that can be used to identify infected systems thus facilitating a targeted “Spyware” clean-up periodically. This capability is also useful to target mobile clients (notebook PCs) that are not protected with Personal Firewalls that become infected whilst outside the corporate perimeter.

Recommendations

In light of the above Orthus suggest that enterprises take the following approach to mitigating the risks posed by “Spyware” today :

* deploy gateway “Spyware” protection to prevent back-channel communication by infected systems augmented with a leading URL filtering solution.

* use granular reporting capabilities from gateway solutions to identify infected systems and choose a dedicated anti-spyware tool to clean-up infected systems on a case-by-case / ad hoc basis.

* do not deploy dedicated anti-spyware programs across the desktop population – instead wait for AV vendors to add strong anti-spyware capabilities in future releases.

* force remote office branch office based systems to access the Internet via the corporate gateway (where gateway anti-spyware protection exists).

* for remote and mobile clients, in addition to AV, install a recognised personal firewall to increase protection.

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In-House Printing

Printed marketing collaterals from business cards to brochures and packaging can now be produced in-house through the Xante Ilumina 502 Digital Color Press. Contracting print jobs with offset printers may be difficult to sustain during trying economic times and considering the required run lengths, businesses cannot afford to have an excess inventory of printed collateral. The key here is to migrate from the usual volume printing to short run printing where only the required number of copies are produced. The Xante Illumina color laser printer efficiently serves short run print requirements as the unit can produce brilliant prints on thick stock and oversized media at a low production cost.

Reloading Empty Toner Cartridges

Now if you are thinking about downscaling glossy printouts to matte, draft copies for inter-office memo and reports, that may be the most prudent way to go. But then again, you don’t have to! Many laser printer users may just have been discouraged by the hefty pricing of replacement consumables such as the toner cartridge and therefore have devised ways to slow down the consumption of toner supply. The black cartridge of the Xante Ilumina 502 printer for instance is retailed at $100 while its cyan, magenta and yellow cartridges sell at $300 a piece. That’s a whooping $1000 to exit your pocket should you purchase all 4 toner cartridges. On the 8th purchase of a rainbow package, total expenditure on consumables has reached the printer unit’s acquisition price of $8000. And that’s hardly good news for businesses engaged in volume print jobs.

Luckily, the aftermarket for printer consumables has come up with third party toner products that are 100% compatible with the consumables of color laser printers such as the Xante Ilumina 502. The printer’s used 200-100222 or cyan toner cartridge can be reloaded with fresh toner supply using a refill toner product such as the Xante Ilumina toner refill kit. The toner refill kit retails for only $86 and includes a bottle of fresh toner powder, a funnel cap, toner wipes, 1 reset chip and an instructional material. At this rate, the user saves as much as 70% from the price of an OEM cartridge. What’s more is that the refilled cartridge produces the same quality prints and yield (15,000 pages at 5% coverage) as the OEM toner cartridge.

The times may call for downscaling and regulated business printing but then these should not come at the the expense of good print quality and yield. In this regard, the Xante Ilumina 502 color laser printer and Xante Ilumina toner refill kit can help sustain the print requirements of businesses while managing costs efficiently.

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One of the primary advantages of mixed-signal microcontrollers is that they can do much more than simply convert external analog signals to the digital domain. Data acquisition is not an end in itself but rather is a first step before extracting the meaning behind acquired data, and deciding what to do with it. Many embedded developers are turning to newer mixed-signal microcontrollers because they make it possible to cost-effectively implement complex digital filtering in a wide range of new applications. More advanced filtering allows engineers to offer more capabilities – including higher precision, better efficiency and lower power consumption – with which to differentiate their products.

Bringing digital signal processing and control functionality onto the same device, however, does not come without its own challenges. When an application requires extensive signal processing, it can become a challenge for the firmware engineer to perform such processing in real-time when it is run on the same processor as all of the other housekeeping tasks the processor needs to support, including managing a screen, keyboard, storage, and so on. Additionally, the architecture must be flexible enough to support changing application specs, as well as be able to scale functionality to meet different market requirements.

Balancing Hardware and Software Resources

Flexibility in an embedded architecture is important. Many embedded applications do not have the volumes to encourage silicon manufacturers to spin application-specific microcontrollers. Even for high volume applications, application-specific chips appear on the market only after the functions they provide have become commoditized. In many cases, if developers want to implement advanced digital filtering, they have to rely upon controllers that are either general-purpose in nature or that are optimized for other applications. In addition, as with many embedded project developments, they go through frequent changes in scope, ambition, and architecture. Keeping up with the impact this has on a monolithic coding project on a single core is challenging, especially with today’s decentralized, multi-contributor design teams.

Some newer mixed-signal controllers provide the necessary flexibility through programmable or configurable logic,implemented as integrated coprocessors or hardware blocks that can be programmed to execute independently, in parallel to the main CPU. These devices can implement compute-intensive algorithms with a high degree of efficiency, and at minimal cost. In addition, the decoupling of signal processing from the main CPU allows the reuse of IP through an ecosystem of blocks that can be shared across a design community to reduce development time and lower application cost. This level of flexibility also allows developers to support entirely new applications with their own custom IP blocks in a cost-effective manner.

Being able to embed signal processing into functional components at the block level ensures that the project’s management can be ‘forked’ at the component design level. By adjusting the programmable hardware resources available to a particular function, developers can scale digital filtering algorithms independently of CPU software resources. This methodology ensures that signal processing load variations, which change as algorithms are modified during the design process, have no impact on other highly timing-critical tasks such as communications management.

Embedding digital filtering

This article illustrates some recent system designs employing a recently-introduced mixed-signal microcontroller with an embedded filter coprocessor. Many filtering topologies can be coded effectively onto this structure. Combining programmable hardware and data path blocks enables developers to marry the efficiencies of hardware with software in an optimal balance for their specific application. Data and coefficients are stored in dedicated local memories and are shared between programmable hardware and software resources via a system bus. Both sets of resources have access to sources and sinks of digital data.

Tools are available for quickly configuring these systems-on-chip using a drag-and-drop interface, such as the PSoC Creator Integrated Development Environment from Cypress Semiconductor, which supports the newly-introduced PSoC3 and PsoC5 architectures. Developers have the option of using or modifying a wide range of existing library elements, or creating new blocks such as custom filters. These elements are then converted into the necessary hardware and software components as dictated by the programmable system-on-chip architecture in use.

Multi-channel filtering

The number of channels that can be filtered concurrently is dependent upon the microcontroller’s architecture. In a software implementation, the available processing resources must be time-sliced, creating a complex array of independent threads that must be serviced consistently to meet real-time constraints. Using interrupts to handle non-real-time tasks,such as refreshing a screen or polling a keyboard, can complicate handling of real-time interrupts significantly.

In programmable hardware architecture, hardware resources can be allocated to each channel. These resources execute in parallel with each other and with the CPU, thus eliminating many of the issues relating to managing real-time interrupts. Consider a consumer audio application utilizing a stereo ten-band graphic equalizer whose filter coefficients are calculated by the CPU on the fly. A stereo audio codec is interfaced to the microcontroller over a standard I2S port clocked from an embedded frequency synthesis system that can produce all standard audio master clock frequencies from a single local crystal. If required, this synthesis system can also be synchronized to the framing patterns of common digital interface formats such as USB. All this is implemented in programmable hardware.

At a 44.1 kHz sample rate, this equalizer uses only a fraction of the available resource and filtering power. The response fitting and coefficient calculation routines can take update information dynamically from local controls directly managed by the microcontroller and also from control protocols arriving over an (embedded) interface from a mobile device used as a signal source and control unit.

This recently-implemented system still has enough resources left to implement a multi-band crossover filter bank. The outputs can be delivered to external DACs or digital amplifiers through multiple I2S interfaces. The super-precise control of frequency response obtained eases the acoustic design of ‘difficult’ loudspeaker enclosure designs,such as the driver subsystems designed for in-vehicle and public address applications. It also allows consistent high quality results from compact multiway acoustic designs in docking units, micro-stereos and flat-panel TVs. High channel-count distributed sound reinforcement and messaging systems benefit from the simplified frequency response tuning, all achieved on the same processor that is managing the user interface, communications and power supply.

Summing up

Introducing a powerful digital filtering engine into embedded applications extends the value developers can deliver to their customers, and it reduces system cost, complexity, and time-to-market. By making use of mixed-signal microcontrollers with programmable hardware signal processing resources, such as the PSoC3 device in these examples,it becomes possible to address the evolving requirements for complex signal filtering as they change during the design process. With them,developers can cost-effectively introduce a wide range of capabilities to enhance their products, from adding ‘stereo enhancement’ functions, to decimation filters for digital microphones, and even advanced control algorithms for industrial sensor conditioning and medical applications.

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How do we refill a Samsung ML 2010 toner cartridge?

First, know the specs of your laser printer – from the type and model to the specific toner replacement cartridge. This is because cartridges are designed to fit and work only with an intended printer model. In the same way, toner refill kits are manufactured for use on specific toner cartridges and the respective laser printer. Therefore, refill toner is not generic across cartridge and printer models. When ordering a toner refill kit, make sure that you are getting refill toner that is 100% compatible with your toner cartridge and laser printer. The process is really simple! Order a kit today and follow the steps supplied with the instruction manual and you can never go wrong; more so because pictures complement the step by step procedures. The kit includes the following items:

a bottle of toner replacement
latex gloves
funnel cap and
toner wipes.

To begin the refill, pull out the empty cartridge from the laser printer and check the removable lid or panel.

Now with your crosshead screwdriver take out the screw holding the removable panel to access the toner chamber.
The hopper cap should now be visible. Unplug it using your flat head screwdriver, but care should be observed as not to cause damage to the hopper cap.
Empty the cartridge of old toner residues, if possible apply sucking pressure to really clean the inside chamber.
Use the ‘no mess’ pouring spout and fill the chamber with the new toner powder and plug on the hopper cap.
Replace the removable lid or panel and wipe the outside of excess toner.

This completes the refill process but before loading the cartridge back into the laser printer, shake the refilled cartridge slightly to loosen the toner powder. You are now about ready for another round of laser printing. In the end, Samsung toner refill kits provide consumers with a viable alternative, not only performance wise but also on reduced cost parameters.

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A simple stamping machine

The simple “stamping device” was the first of over 3,500 patents awarded to the company through its ongoing history. This devise was created to move mail through a company’s mail room more efficiently. This saved the company time and money in an era when business was booming and the industrial age was flourishing in the US. Three years later, the US Government authorized permit mail, followed four years later by the incorporation of the Universal Stamping Machine Company. That same year, the company started selling cancellation machines to the US Post Office.

Pitney and Bowes

In 1919, Mr. Pitney and Mr. Bowes got together and started talking about a merger. In 1920, the merger took place followed by a newer smaller machine at a lesser cost. With the advent of mass mailings and its lower costs the company’s primary product sold well through the depression.

Monarch Marking System Company

Perhaps a forerunner to today’s printing and computer generated printing was the acquisition of the Monarch Marking System Company in 1968. Eventually, this company would go on to develop the bar code with all the ramifications, and new printing options, it brings today. The company once again was at the cutting edge of patent and design.

Moving toward today

Pitney Bowes moved a step closer to today’s “modern” age as it introduced its computer, printer and fax lines to the market in 1986. It also began a services division that could aide customers with their Pitney Bowes postage meter, printer, copier and faxing issues.

In was in 1996 that the company made its move into the “modern mail service realm. Its Personal Post Office was well accepted by small and mid-sized companies working with increased amounts of post related projects. For the most part, the major “over-night” carriers had now become well established and the company was there and ready to serve. The use of bar codes and the company’s familiarity with them also helped push the company’s revenues higher.

It has essentially been able to transfer older technology into the computer/printer age of today. To magnify this accomplishment, all one would need to do is look at revenue from the late 1970′s to 2005 when the company increased revenues from its first billion to 5 billion. Since that time the company has been quick to identify trends and move with them.

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