Meanings

Aaaaaargh----Why do Electricians sound like they are speaking GREEK.

What is all this stuff? Profibus, Ethernet, modbus, control logix, Scada, HMI…

Here's some simple explanations

Like when your wife sends you to the store and tells you what to get and the route to take and to speak Italian to the guy at the store and to look on the top shelf for broccoli and then she asks you all about it when you get home. A set of rules to govern system-to-system use. For example, a protocol might specify communication method, transmission rate, data format or error check method. Set of formal rules specifying how network hardware and software should interact in transmitting and receiving information.

This is a special industrial language commonly used by programmers when trying to get PLC/SCADA/DCS to "talk" to each other on different protocols.

Its Just Math. Algorithms are routines to deal with particular situations; for example, a controller formula to correct temperature in a continuous process.

Analog Just a variable voltage or current. Like a dial clock (Analog) compared to a digital clock Analogue devices are those which communicate via a small electric current. For example: flow meters send a current of between 4mA to 20mA or 0-10 volts. The lowest value would represent no flow at all; the largest would indicate maximum flow.

Analog I/O Module Same as an I/O module except If its input, it gets information from pressure to temperature transducers and stuff. If its an output, it sends information to actuators and stuff which position

Computer Aided Design. This is just a smart computer drawing program. They may allow designers to manipulate parts drawings and simulate processes.

Like ford parts don’t fit on Chevy's See open systems. Closed systems are the opposite to open systems. In other words, they are proprietary.

Computer Numerical Control allows machines to be operated from PLCs or computers by means of a numerical code.

Like a president tells the manager who tells the superintendent who tells the Forman who tells the floor workers who do the work. and then back up the line with the information about it. A Distributed Control System is designed to have a series of decentralized control centers which have some degree of autonomy, but are still integrated into a whole system. The center has hierarchical control over the rest.

Direct Digital Control. Systems which can easily and accurately control building HVAC systems. Guess What…They have their own Protocol---BacNet (Building automation control net), or Lon. These systems are usually associated with building automation. Heating, Air conditioning, Lighting, Fire, Security etc.

Digital devices transmit in bits, i.e. a series of binary numbers, to other parts of the system. It works well with electrical because most things are either on or off. Binary has only 2 numbers in it zero 0 or 1 (on or off--Perfect match)

Different-just one- used in electrical as a term for individual inputs and outputs that are either on or off.

Fieldbus is a generic term used to describe a common communications protocol for control systems and/or field instruments. Although some standard forms have been agreed for instruments, the DCS/PLC/Scada industry as a whole have so far no agreed fieldbus.

Fuzzy logic is designed for situations where information is inexact and traditional digital on/off decisions are not possible. It divides data into vague categories such as "hot", "medium" and "cold".

A gateway is either hardware or software that acts as a bridge between two networks so that data can be transferred between a number of Computers/ DCS / PLC.

Pronounced "gooey" Graphic User Interface; this is an interface which uses graphics rather than characters to communicate. Like operator screens with pictures.

Usually touch screens and computer screens that make it easy to get and input data. Like those screens that waitress touch when they get your order. Also like those signs that tell you how many wigits you produced today. Human Machine Interface. Sometimes these are called Man Machine Interface. See MMI

An Input or Output module, which usually contains several I/O points. Connected to a plc or computer or Scada system or DCS system. If its input, it gets information from pushbuttons and stuff. If its an output, it sends information to valves and stuff.

Local Area Networks are used to link up computers. The best known protocol for LANs is Ethernet. Most plc's can also use Ethernet to talk to computers.

Usually used on Hydraulic cylinders, Ball screws, or electric actuators. It tells the PLC the exact position of these devices. A/b uses QB Modules, Modicon uses Delta Modules etc.

Local Operating Networks is another fieldbus, used by about 2,000 companies. The chips are made by Toshiba and Motorola for the German Echelon. They are then sold onto to various manufacturers.

Each DCS controls a number of loops. These consist of a measurement device, a controller and a valve. Each loop is composed of devices to control the flow of liquid at a particular point.

Eating lunch while talking on the phone and tying your shoes. The ability of a computer to handle more than two programs at the same time.

Like Tires. All cars are made so their tires can be made by anyone. Open Control System. This term is sometimes used to emphasize the lack of proprietary architecture.

Object Linking and Embedding, Microsoft's greatest contribution to industrial control, allows operators to link the same object in several different applications

Open systems are defined as those systems that can be supplied by hardware components from multiple vendors, and whose software can be operated from different platforms. They are opposite to closed or proprietary systems

Used to make decisions on how much you can get in the best way. An example is in a sawmill they run logs thru an optimizer and it adjusts all the saws to get the most value from the log.

Whoa Big term! --this is like your cruise control in your car. Say you hit a hill. It measures how fast you're slowing down and starts adjusting the gas so it wont overshoot too much and keep your speed steady. PID stands for proportional, integral, derivative. Proportional means changing a variable in proportion to its difference from the set-point. Integral rectifies any small difference in the variable and the set-point. Derivative reduces the other oscillations.

A Programmable Logic Controller is a controller which stores instructions to command devices like valves and motors. Originally a relay replace. Now lots more. Profibus The German fieldbus, not to be confused with the common European fieldbus Profibus PA.

This is the name agreed on a common European Fieldbus for process automation, still disputed by mainly American companies. Its main pusher Siemens.

Like an emergency generator in a power outage. This is the ability to switch from primary equipment to standby equipment automatically without affecting the process under control.

Remote Input/Output bus. This is a communication bus used to connect a the main plc with remote I/O points. Used to save wire as you can put the remote rack close to the action

For programming Allan Bradley PLC's This is where you write programs. Every PLC has to be programmed. Most use a computer although some smaller ones have a LCD and/or a handheld programmer.

Supervisory Control And Data Acquisition software. They work a lot like PLC's and DCS's but were built with long distant communications in mind.

The time it Takes a PLC or DCS to do a complete check and update of all its math and I/o and program..The faster the better.

This is a Device that electrically tells hydraulic (&Air) systems how fast and when to move hydraulics. There are also Electric Servo motors that position to very precise positions.

Sequence Function Chart. A programming/configuration language. Like Ladder logic or Function block, or Basic, or assembly language or C++ etc.

Slave modules are distributed modules that report back to a central master. Despite the name, they have their own processing ability. Another name for them is "child" modules

So, There you Have it. I Know the "Gurus" of each definition will shudder, but remember this is for those who don’t know. Hope this helps someone out there. I'll add more as it comes to me....Les