What Is a Programmable Display?
A programmable display is a display/operation device with a built-in computer that can be programmed.
Most of them are in the form of a touch panel. In addition to display and operation, a wide range of products with communication and logging functions are also available.
In most cases, the internal program is developed using dedicated software sold by the programmable display manufacturer.
Uses of Programmable Displays
Programmable displays are used in a wide range of applications, from everyday life to industrial fields.
The following are examples of programmable display applications:
- Vending machines
- Fueling machines at gas stations
- Commercial equipment such as ATMs
- Exhaust gas measurement equipment
- Factory automation equipment
- Car navigation systems for automobiles and buses
- Navigation equipment for ships
A familiar application that has been used for some time is ATMs. Push buttons and guidance are displayed on a touch panel to facilitate operation.
In industrial applications, ATMs are used in conjunction with programmable controllers (PLCs) and other control devices to display information on machinery and equipment. It is generally possible to perform operations as needed.
Principle of Programmable Displays
Programmable displays are mainly composed of a display function, an operation function, and an internal control function.
1. Display Function
The display function shows a screen on the display. It displays information on the status of mechanical devices and operating instructions. In the case of machinery, lamps and meters are displayed, along with a simple system diagram to assist in operation management.
2. Operation Function
The operation function is a function that can be operated by pressing a finger on the touch panel. If the display is programmed to show operation buttons, the buttons can be operated as needed. When a button is pressed, the computer detects it and feeds back to the control device.
3. Internal Control Function
The internal control function is a function that performs status monitoring and logging. In recent years, products with communication and network functions are also available.
Other Information on Programmable Displays
1. How to Use Programmable Displays
Programmable displays require editing software sold by the manufacturer. Consider purchasing software for editing.
In addition, programmable displays often have a separate CPU that performs arithmetic operations, and in most cases, the signal cable connecting the CPU and programmable display is an international standard. Because of the international standard, the CPU and programmable display may be made by different manufacturers.
The following is an example of the communication method used.
RS232C
RS232C signals are the oldest serial communication used. The transmission distance is within 15 m, which is a relatively short distance communication. The number of units that can be connected is limited to one CPU to one display unit.
RS422
RS422 signals have a maximum transmission distance of 1200m and are upward compatible with RS232C serial communication. However, the number of connectable units is limited to a total of 10 CPUs and indicators.
RS485
The RS485 signal is a serial communication that is upward compatible with the RS422 signal. It has the advantage of allowing a larger number of units to be connected while maintaining the same transmission speed.
Ethernet
Ethernet (LAN) communication is the most common method of communication for Programmable Displays in recent years, and is also used to connect PCs and other devices to the Internet via a wired connection, allowing a virtually unlimited number of devices to be connected. It also has the advantage of allowing direct, permanent connections to PCs and the Internet.
However, the maximum transmission distance of a LAN cable is 100 meters. When configuring a network in a high-rise building, for example, a relay method using a HUB is used. In large factories where it is difficult to set up a relay point, a media converter is used to convert LAN signals to optical signals for transmission.
2. Programmable Displays in English
Programmable display is generally called HMI (human-machine interface).
The meaning of HMI is “a device for exchanging information between humans and machines,” and HMI includes the mouse, keyboard, and display on a PC.