Manuals and Videotutorials

Between Merbon RT 2.2.0.5 and 2.4.0.11, there were significant changes in runtime memory organization and memory management on the FreeRTOS platform. Although upgrading is generally recommended and sometimes necessary for installation extensions or organizational reasons, project upgrades can affect the behavior of some runtime features.

Let’s look at the classic control system topology from a safety point of view and find some rules according to which the control system should be designed and installed to be able to be successfully handed over to the operator from a cybersecurity point of view – while operating and servicing comfortably and efficiently.

Operational practice shows that although programming tools and applications sometimes provide a relatively high level of security, their capabilities are not exploited - mostly out of convenience or ignorance of how to set them up correctly. Let's try to think about the following tips and, where it makes sense, actively promote them.

The Building Automation Control Network (BACnet) protocol is not new to building management systems. We will try to introduce you to it gradually.

After runtime upload, some Linux-based PLCs may show incorrect display of special characters on the web and their BACnet server is disabled. This is caused by a missing record in the configuration script which is run after the runtime update.

When designing and commissioning Modbus serial buses, we sometimes encounter situations where it makes sense to switch from a serial link to an Ethernet network and transmit data over it.

Sometimes we get into a situation where the only way to connect two or more controllers to each other or to the headquarters is a serial line - a two-wire line.

When deploying room units UI011, room controllers UC/FC..., as well as 3rd party devices talking Modbus, there appears a problem how to write into variables which are also controlled locally – over a knob, touch schreen, or other manual control.

Although the Modbus standard was defined more than 40 years ago, the protocol still provides reliable and fast communication between programmable logic controllers, sensors, thermostats, frequency converters and other devices. Either the RS485, RS422, RS232 interface (Modbus RTU) or the TCP/IP Ethernet protocol (Modbus TCP) can be used for data transfer.

In systems with fan coils, heat exchangers are often used alternately for heating and cooling. In a classic two-pipe connection with change-over, the whole building (or at least a branch) has to work with one type of energy - it can either heat or cool.

Runtime, or program which runs the application engineered by a programmer, executes the main activity of a PLC. It may be implemented on various hardware platforms.

In the following article, the main principles used in energy data acquisition are described, and we focus on the cooperation between the air conditioning supplier and the BMS supplier.

The IIS server where a Merbon SCADA server is installed should contain a SSL security certificate. Otherwise most of the browsers will consider the site insecure and show warning messages, or refuse to display the web pages completely.

Room and duct CO2 sensors for building control systems are based mostly on the NDIR (Nondispersive Infrared) measuring elements. They measure the diffusion of infrared light caused by the presence of CO2 molecules in the measuring chamber.

System topology description, configuration, process station and modul connection.

There are more communication standards used today. Each of them requires a slightly specific approach. Let us take Modbus RTU (over serial line) or Modbus TCP (over Ethernet), one of the most favourite protocols, as an example to show the whole process and point out the most common problems.

Every control system shall contain a user interface which provides fast overview of the controlled processes and comfortable setting of parameters. The first question in the decision process should be: who is going to work with the system?

Exchange of data between SoftPLC and Merbon systems may be required from the following reasons. Read more about it in this article.

In building with integrated room controls with variable occupation, such as in hotels, building owners often require to set the room to Off  automatically on long-term unoccupation.

Programování v jazyce ST (strukturovaný text) nabízí autorům aplikací značnou flexibilitu. Jednou z často poptávaných vlastností je vývoj komunikačních driverů pro cizí systémy. Na následujícím příkladu si ukážeme, jak vypadá „zákaznický“ driver pro elektroměry Pozyton sEAB.

The preparation of an application program for HVAC equipment should be effective not only in order to minimize the time required for it. It is also a matter of making the most of the possibilities of hardware platforms, but on the other hand keeping some reserve for possible expansion of the system.

Let's recall a few basic rules for mounting sensors: these are simple principles, but not always followed - either out of ignorance or just because someone wanted to simplify their work.

The KNX bus is most often installed in residential objects like family houses, but also on office buildings for illumination and blinds control, or heating and air-conditioning of individual rooms.

The wireless EnOcean-based peripherials are attractive because of their easy installation and no need of batteries. They are powered using solar cells, piezoelectric elements and thermoelectric cells. Their main field of application is at installations where cabling can not be brought to sensors, window contacts or room units because of price, design, or local conditions.

The input/output modules (I/O modules) must be configured as part of the commissioning process. They must be addressed at Modbus, and at some types also measuring ranges for analogue inputs must be set. Most frequently, the I/O moduly are addressed and set up using the ModComTool software and a serial converter, e.g. Domat M080 or some other USB or RS232 to RS485 converter.

The aim of the electrical energy distributor is to keep the consumption curve in time as flat as possible. One of the measures to achieve this is to prevent load peaks at individual customers.

For the installed programs to work properly, they need support of the operating system inclusive its optional extensions or libraries. In the following text, the basic prerequisites for successfull installation and operation of Domat programs and development tools are listed.

Building control systems are highly underestimated regarding network security. There are several reasons for this which are listed in this article.

Apart from the TCP and UDP port numbers listed below, some of the products may support non-IP protocols for device detection in a local network and setting of the IP address and other IP parameters. It is supposed that the products are separated from the Internet (or any other non-secure network) by an IP router which is routing TCP and UDP protocols only.

Passive temperature sensors are the first choice in building control systems. They are cheap and easy to install thanks to their polarity independence, compared to active sensors with voltage or current output. However, deployment of passive sensor may lead to problems, which – and debugging of which – are dealt in the following article.

The PWM signal is used in radio engineering for modulation of the communication signal, in electrical engineering for power control of motors, dimmers and other power elements.

See this article for how to configure and upload.

A properly functioning technical support department is an essential part of any company that wants to offer any technology. In the following, we will look at how Domat Control System technical support works and how you should proceed to get the most out of it.