Reading out meter data via the wired M-Bus and its wireless pendant OMS (wM-Bus) gains more and more in importance. The demand for this technology in industrial environments is growing tremendously. There are some main drivers: the requirement for energy efficiency, the need for energy audits, ISO 50001 and the need for optimizing energy costs. In any case, a growing number of intelligent meters are installed in processes, plant, facilities or real estates. For integrating these meters into a control or automation system it is necessary to translate the meter data to the automation world. Modbus TCP as a de facto standard is suited best for this task.
Modbus is a communication protocol and is considered a quasi-standard in automation technology. It is based on binary data notation and uses a master-slave mechanism (client-server architecture). The principle of data transmission applied for this is simple: Address, instruction code, length specification, data content, and checksum make up the packets. This can be used on a universal level and explains its very widespread application.
But why do discrepancies come up in relation with Modbus communication time and again?
We have created a guide for this purpose.
This guide explores questions like “What is Big and Little Endian?” and gives examples for a better understanding of the sequence of data representation – the Endianness.
Another pitfall to avoid in Modbus is to wrongly address registers or, respectively, storage locations. For this we also give a detailed explanation with examples in our guide.
You can get an overview of our Modbus gateways here.
The devices of the MBUS-GEM product family come with a standard Ethernet interface which supports Modbus TCP in slave mode. The controlling system as a Modbus master is therefore able to access the data of the meters directly using Modbus registers via the connected network. This can also be done in remote or distributed applications.
Likewise, all of our data concentrators are also optionally available with a Modbus TCP extension.
Our Modbus guideline is available for you to download here:
PDF | 218 kB
