WHEATBRIDGE ::Data Acquisition: Global Options

PROJECTS WITH MULTIPLE ENDPOINTS: JUMBOTRONS TO iPHONES

Multi-tiered architecture and Model-View-Control (MVC) design patterns are frequently discussed today. If MVC is truely an "architectural" framework, then add it to the list of 72 other architectures. If it is a design pattern, then it belongs with in a list with 42 other design patterns. While they do cover some of the same territory, they are not identical. What's more confusing is that both concepts have something to add to building programs that are modular and that can serve different types and kinds of clients, such as multi-monitor desktop computers, hardened field laptops with tiny screens, cell phones, smart phones, or even jumbotron/supersigns on Times Square.

A discussion of the MVC design pattern should probably begin with Trygve Reenskaug, who wrote the first paper on the concept while on a sabattical at PARC in 1980 or so. A copy of that paper, which consists of four short paragraphs, can be found here. A Visual Studio MVC application is somewhat larger--the base program, as generated by Visual Studio, consists of 20 directories and 60 files.

At the simplest level we build multi-tier systems that consist of three tiers: the presentation tier, the logic tier, and the data tier. Within the context of the presentation tier the software structure is represented by the MVC model or design pattern. Some applications have very simple structures--there is existing data in the database, there is a need for middleware to convey the data to a web page (for example), and then there is the presentation tier or layer, which is, in this example, a web page. The fundamental rule iof three-tier architecture is this: the client never communicates directly with the data: all communication must pass through the middle tier. These are fairly straightforward systems to implement and usually reflect a web development perspective.

Then there are the applications that go a little deeper into industrial process technologies. These applications must pass through or tunnel through firewalls, they must communicate with devices and be able to configure them. They use more powerful desktop presentation software that communicates directly with the data and doesn't require a middleman to slow things down. These applications are better defined by the Internet Protocol Suite. They have an application layer (SMTP, SNMP, Telnet, etc.), a transport layer (TCP, UDP), an Internet layer (IP (IPv4, Ipv6), ICMP, ICMPv6, IGMP, Ipsec), and a link layer (PPP, ARP/InARP, DSL, modems). Did we neglect to mention a presentation layer (depending upon the client device) too? These sorts of applications are our dish so to speak, and we love building them.

No matter what your needs are, we can help you navigate through this maze. We will strive to help you target multiple platforms, derive your data from multiple sources, and assist in all components of the project. If you already have a plan, however, you can rest assured we will understand the differences between the approaches and have a finer appreciation of your situation.