Mobile data terminal
Encyclopedia
A mobile data terminal is a computerized device used in public transit vehicles, taxicab
s, courier
vehicles, service
trucks, commercial trucking fleets, military logistics, fishing fleets, warehouse inventory control, and emergency vehicles to communicate with a central dispatch
office. They are also used to display mapping and information relevant to the tasks and actions performed by the vehicle such as CAD drawings, diagrams & safety information.
Mobile data terminals feature a screen
on which to view information and a keyboard
or keypad
for entering information, and may be connected to various peripheral
devices. Standard peripherals include two-way radios and taximeter
s, both of which predate computer assisted dispatching. MDTs may be simple display and keypad units, intended to be connected to a separate black-box or AVL (see below) computer. While MDTs were originally dumb terminals most have been replaced with fully functional PC hardware, known as MDCs (Mobile Digital Computers). While the MDC term is more correct, MDT is still widely used. Other common terms include MVC (Motor Vehicle Computer) and names of manufacturers such as iMobile or KDT.
(CAD), many MDT's were custom devices, used with specialized point to point radios, particularly in applications such as police dispatching. While applications like taxi and package delivery often still use custom designed terminals, many CAD systems are switching to common (or ruggedized
) laptops and Wide-Area Wireless IP communications, utilizing the Internet or private IP networks connected to and over it.
For many industrial applications, such as commercial trucking, GIS, agriculture, mobile asset management, and other industries, custom electronic hardware is still preferred. Custom terminals use I/O interfaces that connect directly to industry-specific equipment. They are usually environmentally hardened packages with power supply protection and robust memory file systems that greatly improve reliability and task efficiency. MDT solutions that are based on ruggedized consumer products or consumer available software will typically not have the life cycle duration expected in industrial applications, over 5 years.
A related device classification, specific to the transportation industry, is called automatic vehicle location
(AVL). Mobile data terminals are often used in conjunction with a ¨black box¨ that contains GPS receiver, cell phone transceiver, other radio devices, or interfaces to industry-specific equipment. AVL devices may be simple stand-alone modems or may include operating systems with application space for the system integrator.
.
Mounts are designed for attaching MDTs to mobile workspaces into most notably automobiles, forklifts, boats, and planes. Specialized manufacturers such as Gamber-Johnson and LEDCo build mounts for the specific MDT brands and models and for specific vehicles. Specialized regional metal shops and mount design integrators design MDT mounting hardware for low volume specialized applications such as forklifts and commercial boats.
MDTs generally require specific installation protocols to be followed for proper ergonomics, power and communications functionality. MDT installation companies such as PCN Strategies, USAT Corp. and TouchStar Pacific specialize in designing the mount design, assembling the proper parts, and installing them in a safe and consistent manner away from airbags, vehicle HVAC controls, and driver controls. Frequently installations will include a WAN
modem, power conditioning equipment, and a WAN, WLAN, and GPS antenna mounted external to the vehicle.
Taxicab
A taxicab, also taxi or cab, is a type of vehicle for hire with a driver, used by a single passenger or small group of passengers, often for a non-shared ride. A taxicab conveys passengers between locations of their choice...
s, courier
Courier
A courier is a person or a company who delivers messages, packages, and mail. Couriers are distinguished from ordinary mail services by features such as speed, security, tracking, signature, specialization and individualization of express services, and swift delivery times, which are optional for...
vehicles, service
Service (motor vehicle)
A motor vehicle service is a series of maintenance procedures carried out at a set time interval or after the vehicle has travelled a certain distance...
trucks, commercial trucking fleets, military logistics, fishing fleets, warehouse inventory control, and emergency vehicles to communicate with a central dispatch
Dispatch (logistics)
Dispatch is a procedure for assigning employees or vehicles to customers. Industries that dispatch include taxicabs, couriers, emergency services, as well as home and commercial services such as maid services, plumbing, HVAC, pest control and electricians.With vehicle dispatching, clients are...
office. They are also used to display mapping and information relevant to the tasks and actions performed by the vehicle such as CAD drawings, diagrams & safety information.
Mobile data terminals feature a screen
Display device
A display device is an output device for presentation of information in visual or tactile form...
on which to view information and a keyboard
Computer keyboard
In computing, a keyboard is a typewriter-style keyboard, which uses an arrangement of buttons or keys, to act as mechanical levers or electronic switches...
or keypad
Keyboard technology
There are many types of keyboards, usually differentiated by the switch technology employed in their operation. Keyboards are defined by the number of highly durable switches that are incorporated into the system...
for entering information, and may be connected to various peripheral
Peripheral
A peripheral is a device attached to a host computer, but not part of it, and is more or less dependent on the host. It expands the host's capabilities, but does not form part of the core computer architecture....
devices. Standard peripherals include two-way radios and taximeter
Taximeter
A taximeter is a mechanical or electronic device installed in taxicabs and auto rickshaws that calculates passenger fares based on a combination of distance travelled and waiting time...
s, both of which predate computer assisted dispatching. MDTs may be simple display and keypad units, intended to be connected to a separate black-box or AVL (see below) computer. While MDTs were originally dumb terminals most have been replaced with fully functional PC hardware, known as MDCs (Mobile Digital Computers). While the MDC term is more correct, MDT is still widely used. Other common terms include MVC (Motor Vehicle Computer) and names of manufacturers such as iMobile or KDT.
Technology
In the earlier days of computer-aided dispatchingComputer-assisted dispatch
Computer-assisted dispatch, also called Computer Aided Dispatch , is a method of dispatching taxicabs, couriers, field service technicians, or emergency services assisted by computer. It can either be used to send messages to the dispatchee via a mobile data terminal and/or used to store and...
(CAD), many MDT's were custom devices, used with specialized point to point radios, particularly in applications such as police dispatching. While applications like taxi and package delivery often still use custom designed terminals, many CAD systems are switching to common (or ruggedized
Rugged computer
A rugged computer is a computer specifically designed to reliably operate in harsh usage environments and conditions, such as strong vibrations, extreme temperatures and wet or dusty conditions...
) laptops and Wide-Area Wireless IP communications, utilizing the Internet or private IP networks connected to and over it.
For many industrial applications, such as commercial trucking, GIS, agriculture, mobile asset management, and other industries, custom electronic hardware is still preferred. Custom terminals use I/O interfaces that connect directly to industry-specific equipment. They are usually environmentally hardened packages with power supply protection and robust memory file systems that greatly improve reliability and task efficiency. MDT solutions that are based on ruggedized consumer products or consumer available software will typically not have the life cycle duration expected in industrial applications, over 5 years.
Typical MDT features
-
- 9 VDC to 36 VDC input power.
- SAE J1455 compliant
- Electrical transient protection, such as described in ISO 7637, Electrical disturbance on road vehicles.
- Serial port to connect to a satellite or terrestrial radio transceiver.
- Digital I/O to monitor external events.
- Removable medial or I/O port of retrieving data or upgrading software.
- Wide operating temperatureOperating temperatureAn operating temperature is the temperature at which an electrical or mechanical device operates. The device will operate effectively within a specified temperature range which varies based on the device function and application context, and ranges from the minimum operating temperature to the...
-10 C to 60 C or better. - Drop tested to MIL-STD 810E, which specifies multiple drops from 48" to plywood over concrete.
- Sealed against dust and liquid.
- Connections to industry specific equipment, such as J1708 data bus for commercial truck applications.
- Display technology specific to viewing conditions for the intended industry (LCD, TFT LCDTFT LCDThin film transistor liquid crystal display is a variant of liquid crystal display which uses thin-film transistor technology to improve image quality . TFT LCD is one type of Active matrix LCD, though all LCD-screens are based on TFT active matrix addressing...
, Vacuum fluorescent displayVacuum fluorescent displayA vacuum fluorescent display is a display device used commonly on consumer-electronics equipment such as video cassette recorders, car radios, and microwave ovens. Invented in Japan in 1967, the displays became common on calculators and other consumer electronics devices...
, CSTN). - Integrated un-interruptible power supply, which will ride through electrical brown-outs typical in vehicle installations.
- Internal 802.11b transceiver (depending on target application), possibly with external antenna connection.
A related device classification, specific to the transportation industry, is called automatic vehicle location
Automatic vehicle location
Automatic vehicle location is a means for automatically determining the geographic location of a vehicle and transmitting the information to a requester....
(AVL). Mobile data terminals are often used in conjunction with a ¨black box¨ that contains GPS receiver, cell phone transceiver, other radio devices, or interfaces to industry-specific equipment. AVL devices may be simple stand-alone modems or may include operating systems with application space for the system integrator.
Use in-vehicle
MDTs are most commonly associated with in-vehicle use. This requires the MDT to be anchored to the vehicle for driver safety, device security, and user ergonomicsErgonomics
Ergonomics is the study of designing equipment and devices that fit the human body, its movements, and its cognitive abilities.The International Ergonomics Association defines ergonomics as follows:...
.
Mounts are designed for attaching MDTs to mobile workspaces into most notably automobiles, forklifts, boats, and planes. Specialized manufacturers such as Gamber-Johnson and LEDCo build mounts for the specific MDT brands and models and for specific vehicles. Specialized regional metal shops and mount design integrators design MDT mounting hardware for low volume specialized applications such as forklifts and commercial boats.
MDTs generally require specific installation protocols to be followed for proper ergonomics, power and communications functionality. MDT installation companies such as PCN Strategies, USAT Corp. and TouchStar Pacific specialize in designing the mount design, assembling the proper parts, and installing them in a safe and consistent manner away from airbags, vehicle HVAC controls, and driver controls. Frequently installations will include a WAN
Wide area network
A wide area network is a telecommunication network that covers a broad area . Business and government entities utilize WANs to relay data among employees, clients, buyers, and suppliers from various geographical locations...
modem, power conditioning equipment, and a WAN, WLAN, and GPS antenna mounted external to the vehicle.