Manuals and Videotutorials
Online handbooks and manuals will be added here for easier commissioning and problem diagnostics.
Transition to RT 2.4.0.11 and impacts on the project
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 them so that we can proceed correctly when upgrading to version 2.4.0.11 or later.
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Design and installation of measurement and control in terms of safety
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.
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Programming and configuration of control systems from the security point of view
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.
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Merbon IDE tutorials
On this page you will find videotutorials for Merbon IDE. The themes are: Solution build in simple mode, attachment of PLC, adding and setting I/O module, solution build in full mode, FUPLA editor and debugging.
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SoftPLC IDE tutorials
Videotutorials for SoftPLC IDE: creating a project, I/O module configuration, upload program to PLC, trending online values.
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BACnet - brief introduction to the basics
The Building Automation Control Network (BACnet) protocol is not new to building management systems. In a series of articles we will gradually introduce you to it and guide you through its use.
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Fixing incorrect display of special characters on the PLC web and disabled BACnet server
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. How to fix this easily?
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Modbus routing
When designing and commissioning Modbus serial buses, we sometimes encounter situations where it would be advantageous to switch from a serial link to an Ethernet network and transmit data over it. We have described this in more detail in our two-part series.
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SSCP protocol and the serial link
With the expansion of network technologies we have somehow got used to the fact that even process stations (PLC) communicate with development tools, visualization and other clients via network interface, ie Ethernet with TCP/IP protocol, over which the application protocol is standard (eg BACnet) or manufacturer specific. 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.
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Coupling hardware I/O points
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.
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Modbus communication protocol
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.
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New function of fancoil controller FCR013 for control of six-way valves
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. In modern buildings, however, the requirements for heating and cooling in rooms are often very different or contradictory, and it is in these cases that the use of a four-pipe system with one exchanger can help.
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Properties of hardware platforms with Merbon runtime
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. The platforms have different properties, such as processor computing power, operation memory and flash memory size, types and number of serial communication ports, integrated analog and digita inputs / outputs, etc. These properties determine the functionalities which a particular platform is able to support.
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Air conditioning and energy metering
Measuring energy consumption is a strong topic in all fields, including air conditioning. This task is usually solved by the measurement and control (M&R) professions, nowadays often called "Building Management Systems" (BMS). The following is a brief introduction to the principles of data collection on energy consumption and how the cooperation between the air conditioning system supplier and the measurement and control system supplier looks like.
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SSL security certificate for Merbon SCADA servers
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.
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Autocalibration of CO2 sensors
Room and duct CO2sensors 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.
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Designers' Handbook
Handbook for project designers. Creating topologies and wiring diagrams with Domat components. Description of system topology, modules and process stations connections, system limits, and configuration examples.
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Select the right HMI/SCADA for your control system
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? This article should help your with answering these questions.
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Communication between Merbon and SoftPLC process stations
Exchange of data between SoftPLC and Merbon systems may be required from different reasons. The tutorial how to do the integration follows.
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How to write software effectively in Merbon IDE
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.
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Integration of a hotel reservation system into Domat
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. How to control the room activation, based on the data from the hotel reservation system, is described in following article.
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Customized serial communication driver in Merbon RT
Programming in the ST language (structured text) offers flexibility to application engineers. One of frequently demanded functions is development of 3rd party communication drivers. The following example shows how a customized driver for Pozyton sEAB energy meters looks like.
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Integration of a KNX bus into Domat controllers
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. If there is a building control system installed on the premises, it may be useful to bring all data to a common SCADA or even to interconnect both systems on the automation level.
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Integration of EnOcean peripherials into Domat controllers
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.
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Setting of I/O modules using PLC in Converter Mode
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.
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Load shedding control
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. In terms of contract, it means that the customer must not exceed the maximum amount of electrical energy contracted during a 15 minutes time span. This amount of energy is called a „15-minutes maximum“. If this limit is exceeded, the customer pays a penalty. Achieving and exceeding of the limit is monitored by a digital energy meter installed at the customers‘ premises. The bigger the contracted value, the less risky the plant operation is, but customer pays higher flat fees for higher reserved consumption limit.
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Notes to installations
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.
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Network security at building control systems
Building control systems are highly underestimated regarding network security. There are several reasons for this: Suppliers are companies whose core business is far away from IT security, like construction companies, HVAC suppliers, plumbers, and the like; at the time the system is designed it is not clear how it will be connected to the Internet; and the control system designers do not have the IT background necessary, anyway.
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Security issues of Domat products with Ethernet interface
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.
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Passive temperature sensors and their commissioning
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.
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How to communicate with technical support
We will look at how Domat Control System technical support works and how you should proceed to get the most out of it.
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