CuRA - Customized Register Assignment

Define Modbus registers flexibly, individually and project-specifically

In building automation, it's not just precision that counts - it's also efficiency.
Anyone who works with BMS systems, DDC controllers or integration projects on a daily basis knows that standardized register tables are important, but not always optimal.

With CuRA (Customized Register Assignment), we have developed a function that is currently only available in this form from S+S: The individual, project-specific definition of Modbus registers for each individual data point - flexible, project-specific and fully compatible with existing system architectures.

It is not a "nice to have".
CuRA is the result of our consistent development work - from practice for practice.

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Why we developed CuRA

In countless conversations with system integrators, planners and BMS managers, we hear this again and again:

"The device fits - but the register structure doesn't."

Standardized Modbus tables are useful. But projects are not always standardized. Fixed address logics exist, especially in existing buildings or in large BMS systems:

  • Defined 3xxxx and 4xxxx ranges
  • Historically grown register plans
  • Specifications of international BMS manufacturers
  • Internal integration standards of large project developers

And that has meant every time so far:

  • Elaborate mapping
  • Additional documentation
  • Adaptation of the BMS
  • Time lost during commissioning

As the development department at S+S, we asked ourselves:

Why does the project have to adapt to the device - and not the other way around?

CuRA was created precisely from this customer perspective.

Advantages of Modbus

  • Openly documented

    Specifications and implementation guides are available from the Modbus Organization.

  • Serial or Ethernet

    Modbus RTU uses serial communication; Modbus TCP operates over TCP/IP networks.

  • Standardized functions

    Function codes define the reading and writing of bits and registers.

  • Cross-manufacturer

    Devices from different vendors can be integrated if the interface and data model are compatible.

  • Expandable in a planned manner

    Compatible devices can be added within a suitable network structure.

  • Devices interchangeable

    With compatible interfaces and register assignments, individual devices can be replaced.

  • Integrable into existing systems

    Modbus RTU and Modbus TCP can be integrated into existing automation systems.

  • Scalable according to system architecture

    Additional segments, repeaters or gateways enable the construction of larger systems.

Why is this so valuable?

  1. Time savings during commissioning
    - No or little adaptation of the BMS structure necessary.
    - No additional mapping tables.
    - No complicated gateways or detours.
    - Reduce the number of queries: Arrangement of important registers next to each other (1, 2, 3, 4 instead of 100, 400, 800, 1200) > one query instead of four.

    This significantly reduces planning effort and commissioning time.

  2. Ideal for retrofit projects
    In existing buildings, the register structure is often non-negotiable.
    With CuRA, new Rymaskon® devices can be precisely integrated into existing structures - without system conversion.

  3. Standardized project structure
    Especially for larger projects or series installations (e.g. hotel, office complex, residential complex), CuRA provides:
    - Standardized address logic
    - Clear documentation
    - Reusable GLT templates

  4. Maximum freedom of integration
    CuRA turns a standardized device into a project-specific solution - without the need for custom-made products.

Contents

Technical background to CuRA Practical example CuRA CuRA + W-Modbus - Maximum flexibility

Technical background

Our Rymaskon® support 1000 devices:

  • Modbus RTU (RS-485)
  • W-Modbus (Wireless)
  • Extensive data and configuration registers
  • Holding, input and coil registers
  • Read and write functions via GLT

The devices have a structured register table that defines all available data points. With CuRA, this standard structure is adapted to the specific project - without changing the internal logic of the device.
The function is anchored as a central feature in the product description

Example from practice

A system integrator works with a BMS that specifies the following structure:

  • 30000 range → Actual values
  • 31000 range → Setpoints
  • 32000 range → Status messages

By default, Modbus devices are often in a mixed range.

Without our feature, this means:

  • Adaptation of the BMS
  • Special programming
  • Increased commissioning time

With CuRA, we can easily customize the areas according to our needs:

  • Temperature actual value → 30001
  • Setpoint → 31001
  • Fan status → 32001

Result:
✔ No GLT adjustment
✔ Faster commissioning
✔ Reduced documentation effort
✔ Project deadlines met

CuRA + W-Modbus - Maximum flexibility

CuRA is particularly exciting in combination with our W-Modbus-system. Because:

  • Radio network remains standardized
  • The gateway handles communication and system integration
  • Register structure remains fully customizable

Especially with hybrid networks (RTU + W-Modbus), it becomes clear how important a well thought-out system architecture is to ensure maximum flexibility.

How is CuRA configured?

The configuration can be carried out via:

  • Configuration software (S+S Configuration Tool)
  • Modbus register
  • Project-specific parameterization

Important:
The register adjustment is structured and documented - for a clean handover to the planner and integrator.

Conclusion: Why CuRA is typically S+S

CuRA stands for:

✔ Maximum freedom of integration
✔ Reduced project runtimes
✔ Perfect GLT adaptation
✔ Clean retrofit integration
✔ Professional system architecture

With CuRA, we turn a standardized Modbus device into an individual solution - without the need for custom development.

And thus exemplary for our claim:

We do not develop products that only work.
We develop solutions that simplify projects.

And that is precisely why system integrators, planners and BMS manufacturers have been relying on S+S Regeltechnik.