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Metal Halide

A member of the high-intensity discharge (HID) family of lamps, produce high light output for their size, making them a compact, powerful, and efficient light source. Created in the late 1960's for industrial use, metal halide lamps are now available in numerous sizes and configurations for commercial and residential applications. Like most HID lamps, metal halide lamps operate under high pressure and temperature, and require special fixtures to operate safely. They are also considered a "point" light source, so reflective luminaires are often required to concentrate the light for purposes of the lighting application.



Metasys is a building automation system developed and distributed by Johnson Controls. The Metasys system allows users to control a variety of building functions, such as air-handling systems, lighting, security and utility monitoring by way of the building’s internal network or over the Web.

For a more comprehensive overview of Metasys, visit Johnson Controls



Modbus Protocol is a messaging structure developed by Modicon in 1979. The Modbus protocol is used mostly in the industrial process market to communicate between PLCs (Programmable Logic Controllers). Although there is no official standard, there is extensive documentation on Modbus and most companies who choose to interface using this protocol follow the same format.

Modbus is not a protocol that is particularly well suited for building management because of its limited master/slave structure, but as it is fairly simple to construct an interface, many companies do offer Modbus as an open protocol solution.


Because it is a common open protocol, modbus is a standard offering for OEMCtrl translators and programmable controllers.


Additional Information:


Motion Detector

Often called Occupancy Sensors, Mothion sensor control that uses passive infrared or ultrasonic detection to sense whether someone is present or not, and to turn a light on or off appropriately. Commonly used in outdoor flood or spot fixtures. “Automatic On” sensors turn lights on when presence; “Manual On” sensors require you to press a switch. Both types turn lights off automatically when they no longer sense a presence.


Montreal Protocol

The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances believed to be responsible for ozone depletion and will forces a significant change in the refrigerants permitted in HVACR systems.


ms/tp, ms-tp

Acronym for Master Slave/Token Passing, is a type of LAN implemented using the EIA-485 signaling standard suitable for unitary controller and terminal control communications. To initiate communications on the network, a node will have an electronic "token" which is passed from one node to another around the network. Master devices are allowed to have the token, whereas slave devices are allowed only to respond to requests from master devices.


The speed of an MS/TP network ranges from 9600 baud to 76.8K baud.



Acronym for multistate-value.