Human Machine Interface

The term HMI has now become fully established in the world of automation. It usually refers to the operating unit of the machine or system. This can be a control panel with switches, buttons and lamps, but nowadays it is often also a display, usually with a touch screen or a combination of both.

At Wachendorff, the term HMI is used almost exclusively in connection with operating devices with a touch display. These fall under the Operating & Monitoring product group, or B&B for short.

An HMI is a device with which a person can operate the machine. An IPC is a PC as we know it from the office sector, for example, but with an industrial design, mechanical and thermal load capacity, housing, display, etc. An IPC can also run an operating system, making the IPC a kind of HMI.

An HMI, Human Machine Interface, is usually an operating device with buttons and/or touch display. The user interface that can be seen on the HMI is often created with software on a PC and then transferred to the HMI. The user interface is effectively the project or the application that runs on the HMI. How exactly this works on the HMI is actually irrelevant for the user. In most cases, the HMI has an operating system on which an application runs that executes the project planning, i.e. the user interface itself, on the HMI. The number and type of interfaces and protocols that the HMI has or that the configuration software makes available are very important for an HMI.

An IPC is basically a normal PC with a mainboard, processor, RAM and hard disk space and usually also with a commercial operating system such as Windows, Linux or similar. However, the IPC often comes in a completely different housing and the components used are much more robust and can operate in a wider temperature range than standard PCs, e.g. in the office sector. An IPC is used to control machines and systems in an industrial environment or the devices work in this area. An IPC is optimally equipped for its tasks in this area.

An HMI, Human Machine Interface, is usually configured with the appropriate software on a PC. Screen masks and user interfaces are designed and created with these mostly graphical tools. Graphical control elements such as switches and buttons, but also bar graphs, trend graphics and other graphical display and input objects are often available here. The application is then compiled on the PC, generating machine code that can run on the HMI. The compilation is then downloaded to the HMI, serially or nowadays mostly via EtherNet, and then executed on the HMI by a corresponding application, runtime or firmware. During the development of an HMI project, this process is repeated very often and must be carried out again and again because the effects of changes in the project planning must then be observed and assessed in real life on the device.

Wachendorff HMIs are configured using the "EasyBuilder Pro" configuration software. The software is free of charge and includes a simulator for initial tests without real hardware.

The number of drivers is a key criterion for the usability and flexibility of an HMI. The drivers are also always dependent on the interfaces offered by the device. For example, a CANopen driver cannot be used if the device does not have a CAN interface.

Wachendorff HMIs generally all offer at least one, usually two, EtherNet interfaces. Often also serial interfaces RS232 and/or RS485. Some devices also come with a CAN interface. Some devices also offer MPI/Profibus, but with restrictions regarding the speed that can be set for MPI/Profibus. Most operating devices can use Profinet, although not RT (Real Time) but the ISOonTCP variant, which is also used by programming devices to read/write variables and transfer programs. Other fieldbus systems that do not run via the above-mentioned interfaces are not available. No other interfaces can be installed. However, additional protocols are constantly being implemented, so there are currently more than 200 drivers available in EasyBuilder Pro.

A complete list of the available drivers, data types and all information on the respective driver can be found in the PLC Connection Guide,
which you can also find in the Operating & Monitoring download under "Manuals".

Weintek uses the term "Smart HMI" for its cMT devices. "Smart" because the cMT devices have a very elegant design with a silver edge and are only 27.6 mm deep and weigh just 1.6 kg. Extremely fast image switching thanks to quad-core 32-bit RISC with 1.6 GHz. The devices have an integrated media player, browser or PDF viewer and can play audio files and provide haptic feedback (vibration). But what is really smart is the ability to program gestures on the device and assign user-defined functions to them. This allows the operation of a machine to be based on the operation on a smart phone. Many functions, such as the system menu for display brightness, volume, cursor, etc., can be operated in the same way as on a smart phone.

Smart HMIs are cMT devices. A cMT device stands for an alternative operating concept and can fully exploit its advantages in a networked production environment.
(see FAQ "What is a cMT device?" or The smart HMIs of the cMT series)

A cMT device is an HMI with an alternative operating concept. The cMT devices split the classic HMI into two parts, the so-called cMT server and the cMT client.
The cMT server is the part of the HMI that provides the interfaces and protocols and handles communication with the external devices. The cMT client is the part of the HMI that represents the user interface and allows the user to interact with the device. Several cMT clients can be operated on one cMT server.

Up to 9 additional operating instances, so-called cMT clients, can be operated on an HMI as a cMT server. A cMT client (cMT viewer) can be a display from the cMT series, but also a PC application or an app on a smartphone or tablet (Android/iOS).

Each cMT client is a separate operating instance, i.e. each instance runs independently and each instance can display and operate different visualization content. This is made possible by the fact that the clients retrieve the complete visualization from the server when the application is started and the visualization then runs as an independent instance on the respective client. At runtime, only actual data is exchanged between the client and the server; the complete visualization is not sent via the interface, but only the currently relevant data is transferred. This allows the performance of the client hardware to be fully utilized. This gives the user a great user experience. Page loading is very fast and fluid. Reactions to user input are immediate! Many applications are only possible through the use of cMT devices. For example, the operator can use gestures familiar from smartphones to zoom, change pages or quickly access menus and special functions (see The smart HMIs of the cMT series).