Wide temperature HMI is a specific type of HMI that is designed to function in extreme temperatures.

 Software

Mochuan wide temperature metal screen is a full metal shell, better heat dissipation, stronger anti-interference ability; ARM cortex-A8, high computing speed, support a variety of picture formats, support animation format, isolated power supply, the host board with three anti-paint treatment, adapt to a variety of harsh environments.

Application

If there are requirements for the temperature of the working environment, such as constant cold or high temperature environments, orthere are metal enclosures to solve some of circuitry issues in the project, it is recommended this series.

 Hardware

Wide temperature range, support working temperature -20 with 70 degrees, storage temperature -30 to 80 degrees; photoelectric isolation communication port, better protection of serial port reliable operation; up to 4 way serial port, with Ethernet port, CAN port and SD card, support USB main port, stronger expansion ability; high resolution, high brightness, LED backlight, more energy saving and environmental protection. This wide temperature metal  shell series  supports 4.3, 7, 9.7'' 10.4, 12.1 and 15" for customers to choose.

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 Working Principle

Industrial wide temperature resistive screen use new liquid crystal high and low temperature application technology, the product that does not need to heat or brighten can work normally at low temperature. The basic principle is as follows: liquid crystal at low temperature(-40℃) does not freeze or undergo a physical transformation, otherwise neither the heating method nor the brightening method would work, so we though of using software to correct the drift of its electrical characteristics, Managing to trigger the operation of the liquid crystal at low temperature. This requires adjusting the driving timings of the liquid crystal and so on. Through a lot of experimental reserach and extensive application.This technology has become very mature, regardless of how the ambient temperature changes, by widening the trigger timing and matching the correspoinding driver can ensure the normal operation of the LCD.

1. Capacitive hmi screen work by using contact sensors to generate an induced voltage on the conductors on the screen surface, which generates a relative current to measure the touch point by distance. In colder tempreatures, the skin surface of the hand has a low moisture content and dry, cold skine conducts poorly. Also, at lower ambient temperatures, the performance of the sensor is affected and the industrial touch display cannot identify the touch position well enough to case the touch screen to malfunction. Touch screen operating temperature is usually in the -5℃ to +60℃, especially in the winter, the nortern region is more obvious impact.

2. Resistive hmi touch screens are less affected. On the one hand, this is becuase the process used is different and the touch screen is connected by a miniature circuit that is weakly influenced by the temperature. On the other hand, the level of technology of resistive screens is also relatively mature, the materials used are tested and inherited. The temperature requirement for resistive screen is between -20℃ and 65℃, which can meet most of the usage environment.