Posts Tagged ‘definitions’

Here you will find short, no nonsense, non jargon explanations for any terms used that you may be unfamiliar with. While trying to keep this section as short as possible, we feel it is most important that the terms used are fully understood.

Analogue: This refers to an input usually (or output occasionally) that is a variable. That is such a thing as a temperature reading from a sensor would be an analogue input, because it varies over time.

Application: Applications are specific pieces of software to perform specific tasks. Probably the best known application would be Microsoft Word. SIMplicity is a combination of an application and hardware.

Bus: A name commonly given to what is usually 2 or 3 wires, running around a property, or even wireless, and which carries data. SIMbus is 3 wires, carrying power (24 volts DC + and – and one data wire. A bus with 3 wires allows you to supply low voltage power to sensors, and input and output devices, as well as accept data from them.

Comms Unit: (Communications) This device interfaces between the PC and the bus. With the Simplicity system, it plugs into a USB or serial port on one side and the 3 bus wires on the other.

Device: Anything attached to the bus. See explanations for outputs, inputs and sensors, as well as analogue and digital.

Digital: Digital refers to something that has only 2 states, either on or off. It can apply to both inputs and outputs. For instance we would use a digital output (a relay) to turn on a light or a motor.

Direct Current: Refers to current (electricity) flowing in one direction only, as opposed to AC or alternating current, which actually changes direction at about 50 times a second, depending on which country you are in.

Hard wired: Refers to anything that is permanently wired to a system. In the house high voltage system, the oven for instance would typically be hard wired. A stereo with a plug on the end would not, but the power point it plugs into, would be considered hard wired.

Input: An input can be either analogue or digital and refers to anything that puts information into the system. An analogue input is a variable such as a temperature reading, a digital input is something in one of 2 states e.g. a light switch (low voltage) might be connected to a digital input.

Module: A module is a part which can be added to the base platform. Almost any combination of modules can make up the system. To differentiate between hardware and software, we only refer to software as modules

Multidrop: Multidrop refers to the ability of a bus to have additional devices “dropped” or connected onto it. As long as each device has a different address, devices can be connected up to the limit of the system. Simpler systems are not multidrop, each device needs to be connected to the controller separately.

PCB: Printed Circuit Board. What electronic devices have all their parts mounted on.

Poll: This is what we call when each device is asked for it’s status. For a sensor it may be it’s present reading, for an output, it may be the status of a relay, is it off or on? Each device attached to the bus is “polled” or questioned at preset intervals. With Simplicity 4-6 devices are polled every second, depending on the speed selected for the bus.

Power supply: A power supply is a fancy name for a transformer. essentially this will convert 240 volts AC mains power into 24 volts DC to run the bus. We suggest a couple of 12 volt batteries connected in series to give 24 volts DC should “hang off” the system somewhere, to supply backup during mains failure.

Protocol: The “communications language” that is written to communicate with the devices on the bus.

Output: Output refers to anything that is controlled by the PC or PLC. They are usually digital such as a vent motor or a pump.

Relay: A relay is just a stepping device, to turn something bigger on or off. The relays in our Output Unit are a step up from the switches in the microprocessor heart of the unit. They are big enough to switch something like an irrigation solenoid or LED lighting, but should themselves switch a bigger relay or contractor for high voltage devices.

RF: Stands for Radio Frequency, in short wireless. We use wireless in several devices, because in those devices it is more efficient than wiring. For instance The Water Watch can be either wired or wireless, because it gives more flexibility.

RoHS: Stands for Reduction of Hazardous Substances, mainly lead in the solder used in PCB’s. The electronics industry around the world is slowly moving towards RoHS products.

Simplicity: The first 3 letters stand for Simple Interface for Managers.