Since 1.7.5 software version DOMIQ/Base can be used as a segment coupler in the LCN installations. This result in three important advantages:
- Reducing the installation costs – LCN-SK modules become expendable.
- Speeding up of LCN programming – LCN segments can be programmed in parallel using multiple LCN-Pro connections at the same time.
- Local logic – you can implement local timers and logical rules in each segment.
Further in this tutorial we present how to create LCN segment network using DOMIQ/Base modules.
1. LCN Segment Network #
LCN segment network was designed for large building automation installations. Up to 250 modules can operate in a single segment, whereas single LCN installation can be divided into max. 120 segments. This adds a maximum of 30 000 units in the installation. Segments are numbered in the range of 5 to 124th. Addresses from 1 to 4 are reserved. Address no. 3 is a broadcast address and it is used when there is a need to send out information to all available segments. Segment address No. 4 is used to send global messages to all segment couplers.
The division into segments has several advantages:
- Creating independently controlled areas, that can comunicate with each other, such as floors in a building, or building with building, etc.
- Increased clarity of the installation – large installation divided into smaller pieces is easier to manage and programming.
- Higher speed of data transmission. Segmented installation processes data much quicker than one segment with a lot of modules.
The traditional LCN segment network is presented in the following diagram:
There are some limitations due to hardware capabilities of LCN-PK and LCN-SK modules.
LCN-PK can exchange data between PC and LCN-SK only at speed of 9600 bit/s. In large installation (large amount of data to be exchanged) it greatly reduces the comfort of the configuration and programming. In the biggest known LCN installations, duriation of reading whole installation is counted in days!
If you use a dedicated LCN visualization system, low data transmission speed also affects the response time of visualization. Changes in the system are presented with a delay. Another limitation of traditional LCN segment installation is that you can programm remotely only a single segment at a time.
All mentioned limitations disappear when using DOMIQ/Base modules in place of the LCN-SK. Structure of LCN segment network with DOMIQ/Base modules as segment couplers is presented in the following diagram:
Analyzing the diagram above, we can see that LCN-PK module is no longer needed. Thanks to that we eliminated the weakest link of the LCN segment network. Base modules can exchange data at speed of 100Mbit/s (LAN). This provides a great workflow.
Single Base module allows to programm unbounded number of segments simultaneously.Having few computers with LCN-Pro software, you can greatly speed up the work by programming segments in parallel (dotted lines in the diagram).
2. LCN Configuration #
The first step is to configure LCN modules using LCN-Pro software. We used version 3.81.
In order to provide, that Base module reads the LCN modules status changes properly,
their properties have to be set to send global status messages:
- Choose a LCN module and then click op Properties.
- In the window that appears, check Show extended. Then check Status messages active and select Global messages from the drop-down list.
In the properties window of a segment coupler (Base module), transmission parameters are displayed. In present form they are informational only. Do not change these settings. This can cause abnormal communication with the other segments.
3. DOMIQ/Base Configuration #
3.1. General Information #
Since version 1.7.5 Base configurator has a new tab – the Links tab
The Links tab allows us to define intersegmental communication. Using the Links tab you can also create direct point to point connections between two Base modules. This functionality is presented in a separete tutorial.
A framework of the LInks tab is very similar to the Events and Timers tabs. The left side of the window is the Structure. It contains a list of defined groups and connections. Groups are used to connect and communicate bigger groups of Base modules, including intersegmental communication.
In the right side of the Links tab, there is the Details section, in which connection parameters are configured. We will focus on Name, Address and Password parameters.
In order to provide intersegmental communication enter LCN in the Name field. Any other name will prevent communication between LCN segments.
In the intersegmental communiacation Base modules use multicast IP to exchange information. In the multicast IP, according to RFC 3171, the IP addresses are assigned in range from 224.0.0.0 to 239.255.255.255. By default Base uses multicast IP 239.255.255.44 and port: 44544. You can leave the Address field blank if you want to use default IP and port. Otherwise enter IP from range mentioned above. Remember that each Base within particular group must have the same multicast IP address.
If you fill the Password field, the exchanged data will be encrypted.
Below Details section, there is a list of all Bases present in the installation.
3.2. Configuration Example #
Each DOMIQ/Base module with software 1.7.5 or newer includes a default configuration, which enables LCN intersegmental communication. Configuration presented further in this section is a modification of a default one. We changed the Address and Password to present full configuration options. Intersegmental communication is defined by the following procedure:
- Add a group in the Links tab.
- In the Name field enter LCN.
- You can leave the Address field blank if you want to use default muticast IP. Otherwise enter IP from range mentioned in section 3.1. In our example we used: 239.255.255.45.
- You can also leave the Password field empty if you don’t won’t the data to be encrypted.
Otherwise enter a password. In our case: routing.
- Choose the Settings tab, in the Segment field enter the number of the LCN segment.
- Check Events for other segments to allow Base module to react on Events from other segments. It also enables Base module to keep the state of LCN modules from other segments.
- Repeat whole procedure in other Base modules.
3.3. Application #
As we mentioned in the introduction to this tutorial, using Base module as a segment coupler allows us to react on changes of state of devices from the other segments. It means that we can create events, timers, Lua scripts or visualizations which involve LCN modules from other segments. The operation principle and channels syntax doesn’t change, you need only to remember to change segment number.
Example
As an example we will present creation of an event, which will be triggered by switching on a dimmable output from the other segment.
Let us assume that the segment number is 10, the module ID is 11 and output number 1
Add an event, in the Name field type: E.LCN.output.10.11.1 and in the Data enter 100.
Next declare actions to be performed when the event is triggered.
REMEMBER! The only difference is definitions involving modules from other segments is the segment number.
