https://doi.org/10.37815/rte.v37nE1.1360

Original articles

Development of a Protocol Converter
from SMA Data to Modbus TCP for SCADA Integration

Desarrollo de un Convertidor de Protocolo de SMA Data a
Modbus TCP para la Integración SCADA

Santiago Ismael Araujo
Ochoa1 https://orcid.org/0009-0006-8903-4849,
Joe Fernando Tigre Quituizaca1 https://orcid.org/0009-0001-2301-9922, Juan Diego Belesaca1 https://orcid.org/0000-0001-8609-0358, Fabian

Astudillo-Salinas1 https://orcid.org/0000-0001-7644-0270

1Universidad de Cuenca, Departamento de Ingeniería Eléctrica, Electrónica y
Telecomunicaciones, Cuenca, Ecuador

[email-masked], [email-masked], [email-masked], [email-masked]

Sent:

2025/06/29

Accepted:

2025/08/24

Published:

2025/10/15

.

Esta
obra está bajo una licencia internacional Creative Commons Atribución-NoComercial 4.0

Abstract

The integration of distributed energy resources into
smart microgrids frequently necessitates seamless communication between heterogeneous devices and centralized supervisory systems.
However, specific power electronics equipment, such as the SMA Sunny Island inverter,
relies on proprietary communication protocols that are incompatible with standard SCADA interfaces.
The present work delineates the
design and implementation of a protocol converter that facilitates transparent translation between SMA Data and Modbus TCP, thereby enabling native integration
of the Sunny Island inverter
into Modbus-based SCADA environments. The proposed converter
was developed using a Raspberry
Pi platform and employs a modular architecture that combines
the YASDI communication library with a custom Python-based Modbus TCP server. The system
retrieves operational data from the inverter, maps it to Modbus input
registers, and allows configuration commands to be issued from the SCADA system
and applied to the inverter
in a controlled manner.
The experimental validation was carried out in the Microgrid Laboratory at the University of Cuenca. In this setting, the converter
demonstrated reliable performance in two specific tasks:
data acquisition and parameter configuration. The response times
exhibited a range of 10 to 30 seconds, contingent upon the system's
state. Following power cycles and communication interruptions, the converter
demonstrated complete recovery capability. The

findings substantiate the
viability of the proposed method as a cost-effective and resilient solution for integrating proprietary energy devices with industrial monitoring platforms. Its flexibility and resilience
render it suitable
for broader deployment in smart grid infrastructures and distributed
energy management systems.

Keywords: microgrid, inverter,
Modbus, SMA data, gateway, converter.

Resumen

La integración
de recursos energéticos distribuidos en microrredes inteligentes suele requerir una comunicación
fluida entre dispositivos heterogéneos y sistemas de supervisión
centralizados. Sin embargo, ciertos
equipos de electrónica de potencia, como el inversor
SMA Sunny Island, dependen de protocolos de comunicación propietarios que son incompatibles con las interfaces SCADA estándar. El presente
trabajo describe el diseño y la implementación de un convertidor de protocolos que facilita la
traducción transparente entre SMA Data
y Modbus TCP, lo que permite la integración nativa del inversor Sunny Island en entornos SCADA basados en Modbus.
El convertidor propuesto se desarrolló utilizando una plataforma
Raspberry Pi y emplea una arquitectura modular que combina la biblioteca de comunicación YASDI con un servidor Modbus
TCP personalizado basado en Python. El sistema recupera los datos
operativos del inversor, los asigna a los registros de entrada Modbus y permite
que los comandos de configuración se emitan desde el sistema SCADA y se apliquen al inversor de forma
controlada. La validación experimental se llevó a cabo en el
Laboratorio de Microrredes de la Universidad de Cuenca. En este entorno, el
convertidor demostró un rendimiento fiable en dos tareas específicas:
la adquisición de datos y la configuración de parámetros.
Los tiempos de respuesta oscilaron entre 10 y 30 segundos, dependiendo del
estado del sistema. Tras ciclos de alimentación e interrupciones de la
comunicación, el convertidor demostró una capacidad de
recuperación completa. Los resultados corroboran la viabilidad del método propuesto como solución rentable
y resistente para integrar
dispositivos energéticos patentados con plataformas de monitorización
industrial. Su flexibilidad y resistencia lo hacen adecuado para un
despliegue más amplio en infraestructuras de redes inteligentes y
sistemas de gestión de energía distribuida.

Palabras clave: microrred, inversor,
Modbus, SMA data, puerta de enlace, convertidor.

Introduction

Supervisory Control and Data
Acquisition (SCADA) systems play a crucial role in managing distributed energy
resources within modern microgrids. These systems facilitate centralized control,
real-time monitoring, and historical data visualization across
a diverse array of distributed energy resources
(DERs), including smart inverters, energy meters, and storage systems (Li et
al., 2017). Typically, communication between these devices and the SCADA system
relies on standardized industrial protocols, such as Modbus TCP/IP, which
provide a uniform and robust framework for interoperability (Kermani et al., 2021). However, a significant
number of commercially available
inverters continue to operate using proprietary communication protocols,
thereby limiting their direct integration into open SCADA platforms.

The
University of Cuenca's
microgrid laboratory has installed several
pieces of energy generation and management equipment
(Espinoza et al., 2017), including the Sunny Island inverter (SMA,
2015). One of the most significant challenges is integrating of the SMA Sunny
Island inverter family, which utilizes the proprietary SMA Data protocol for communication with SCADA systems
that use the Modbus protocol.
Unlike Modbus, the SMA Data protocol is not

openly documented and lacks native compatibility with
SCADA environments. It requires the use of intermediate solutions to bridge the protocol gap. Several studies have examined protocol
conversion in the context of industrial automation and smart grids. For
instance, Suryani et al. (2024)
reviewed Interoperability in Microgrids, emphasizing the complexity of
translating proprietary formats into open standards. Most efforts to convert protocols in the literature focus on bridging open but heterogeneous interfaces, such as Modbus RTU, MQTT, and IEC 61850, rather than undocumented, proprietary formats. For example, Si et al. 2021 describe middleware
that translates Modbus RTU into MQTT to enable cloud compatibility in
smart microgrids. Similarly, Hemmati et al. (2021) evaluated the interoperability of the IEC 61850 protocol in hardware-in-the-loop microgrid
testbeds, highlighting the need for translating between heterogeneous
communication standards.

Despite these advances, a lack of
documented, low-cost, and field-tested methods remains for converting SMA Data to Modbus TCP/IP
in microgrids. Most existing solutions are commercial black boxes or require deep customization at the firmware level, which complicates
reproducibility and academic validation. The absence of standardized
translation strategies hinders the effective integration of inverters and data
acquisition in research environments focused on energy transition and
intelligent grid control.

The
following article presents
the design, implementation, and laboratory validation of a protocol conversion system that bridges
the proprietary SMA Data protocol
and the Modbus TCP/IP protocol. The conversion architecture is developed using
low-cost embedded hardware and custom software, deployed in
the Microgrid Laboratory at the University of Cuenca. The system intercepts SMA Data communications from Sunny Island inverters and translates these into standardized Modbus register
formats compatible with existing SCADA infrastructure. The converter facilitates seamless integration with SCADA systems
without the need to modify inverter firmware or use proprietary SMA modules. It is achieved
through the implementation of real-time parsing, data
mapping, and Modbus frame construction. The
experimental results demonstrate the successful recovery of real-time measurements (e.g., voltage,
current, power) through Modbus polling, thereby
substantiating the interoperability and usability in both grid- connected and islanded operational
modes.

This contribution addresses a
significant gap in the extant literature by providing a documented, replicable,
and cost-effective solution for integrating legacy SMA Sunny Island inverters, especially those without native Modbus
support, into open SCADA platforms.
The approach is scalable and adaptable to other proprietary protocols aligning with modern microgrid
research demands for reproducible and standardized data acquisition.
Finally, the remainder of this manuscript is organized as follows: The second
section delineates the materials and the
experimental methodology that were utilized in the construction and evaluation
of the protocol converter. In Section 3, the results of the converter's validation are presented, including
performance metrics and interoperability tests.
Section 4 discusses the implications of this work and outlines potential paths for
future enhancements.

Materials and Methods

This section outlines the experimental configuration and methodological framework used to design, implement, and validate the converter tool that translates the SMA Data protocol into Modbus TCP/IP. First, the physical
and network environment of the Microgrid Laboratory is described, with a focus on the Sunny Island inverter and the existing
SCADA infrastructure. In the
following section, an exposition of the hardware
and software architecture of the conversion system is provided.

Experimental Setup

The protocol converter under
consideration was developed and validated within the Microgrid Laboratory
of the University of Cuenca, an academic facility with a focus on research
and development in distributed energy systems. The laboratory is equipped with a hybrid energy
configuration, comprising
photovoltaic generation, an Ampere Square S inverter, an SMA Sunny Island inverter, and a diesel-based backup system (Gutiérrez Otavalo & Padilla
Guamán, 2024). These components are interconnected through
a fiber-optic ring that links multiple operational devices with a centralized
SCADA platform.

The SCADA system is responsible for acquiring and displaying real-time measurements of electrical parameters, as well as storing historical data and triggering event-based alarms. The primary
means of establishing communication between the SCADA server and field devices is through the use of Modbus TCP/IP.
Devices such as smart meters
and Programmable Logic Controllers (PLCs) are natively
compatible with this protocol. However, some aspects within the microgrid,
notably the SMA Sunny Island inverter, operate using proprietary communication
standards. In this case, the SMA Data protocol is transmitted via the Speedwire
interface. This absence of
protocol compatibility poses a substantial integration challenge, as it hinders
the direct acquisition of inverter data by the SCADA system.

This environment provides a realistic and operationally demanding testbed for evaluating the performance of the developed
protocol converter. The integration of the converter into the existing communication infrastructure
facilitates the assessment of its capacity to extract pertinent data from the
SMA inverter, as well as its interoperability within a live SCADA- monitored
microgrid environment.

Communication Context
and Integration Challenge

The
integration of DERs into modern microgrids is contingent upon the standardization and interoperability of
communication protocols. SCADA systems
are designed to aggregate and manage data from heterogeneous sources using open
communication protocols. Among these protocols, Modbus TCP/IP has been adopted
most widely in industrial and academic applications. This protocol enables the SCADA system to query specific data registers on remote
devices, facilitating real-time monitoring, historical logging, and event
management.

In
the case of the Microgrid Laboratory at the University of Cuenca, most field devices, including power meters and PLCs,
are inherently compatible with Modbus TCP. However, specific equipment, such as
the SMA Sunny Island inverter, is not compatible. This inverter employs the SMA Data protocol, a proprietary
communication standard developed by SMA. The protocol is transmitted via Ethernet through the Speedwire interface. In contrast to Modbus,
the SMA Data protocol does not disclose
public register maps or function
codes that a standard
SCADA system can directly interpret.
Consequently, this absence of interoperability hinders the SCADA from accessing
inverter parameters, such as voltage, frequency, state of charge, and
power output. These parameters
are indispensable for effective monitoring and control functions
within a microgrid environment.

To
address this limitation, a gateway device
was introduced as an intermediary between the inverter and the microgrid's local area network.
This gateway is deployed on a Raspberry Pi 3 and captures the proprietary SMA Data frames, processes them, and responds
to Modbus TCP requests issued by the SCADA server.
In this manner, the gateway
effectively emulates a Modbus-compatible device, thereby enabling
the SCADA system
to retrieve inverter
data as if it were communicating with any other standard field unit. This approach obviates
the necessity for invasive
hardware modifications or firmware alterations on the inverter itself.

The
communication topology resulting
from this integration is illustrated in Figure
1, which delineates the physical connections between the SMA Sunny Island
inverter, the gateway, and the SCADA network. As illustrated, the gateway plays a pivotal role in facilitating
bidirectional information exchange between a closed, proprietary device and an open monitoring
architecture.

Figure 1

Simplified communication topology

Converter Deployment and Functional Overview

Two
primary roles characterize the converter’s functionality. Initially, it establishes and maintains communication with the inverter
through the SMA Data protocol
over a Speedwire. Subsequently, it exposes operational data from the
inverter as Modbus TCP registers, thereby making it accessible
to the SCADA system as if the inverter were a native Modbus agent device.

The
sequence of events
starts when the converter makes
a request for and subsequently obtains real-time
operational data from the inverter. It is facilitated by the utilization of the
YASDISHELL program and the YASDI libraries (Eckhard M; Pknowledge). These data include
critical parameters such as input/output voltage, current, power,
battery state of charge, and device status. Each data point is stored
temporarily in intermediary files (SPOTCHANNELS. txt and PARAMCHANNELS.txt) on
the Raspberry Pi.

Subsequently, a Modbus TCP server implemented in Python (named
Server_V7) reads these intermediary files and maps the extracted values into input registers. This mapping adheres
to Modbus conventions, thereby ensuring compatibility with standard
SCADA clients. The server maintains these registers in memory and updates them continuously as new data arrives.
Furthermore, the server facilitates TCP socket communication to receive write
requests from the SCADA system
and, when authorized, directs these requests
to the inverter via an additional
shared file (SetInformation.txt), thereby
serving as a control interface. The complete development of the SMA Data to Modbus TCP/IP protocol converter
is available in the repository https:// github.com/fabianastudillo/microred-sunnyisland-ampere.git.

Figure 2 provides a detailed
schematic of the data transformation pipeline managed by the converter. The figure illustrates the process of retrieving the inverter's data through
the SMA Data protocol. The YASDISHELL application parses the protocol, and the
data is stored temporarily in structured text files. The data is subsequently
mapped to Modbus TCP input registers. These
registers undergo continuous updates and are transmitted to the SCADA client via a standard
TCP/IP Modbus interface. This modular pipeline
facilitates decoupled data handling and ensures compatibility
between heterogeneous communication standards.

Figure 2

Data flow pipeline
from SMA inverter
to SCADA via converter

As illustrated in Figure 3, the
sequence diagram delineates the standard read and write operations between the SCADA client
and the SMA Sunny Island inverter via the Raspberry Pi gateway. The diagram
also illustrates the recovery behavior during a temporary communication outage.
The diagram under consideration highlights the role of the file-based IPC (SPOTCHANNELS.txt / SetInformation.txt) and the YASDI bridge in facilitating of SMA
data conversions.

Figure 3

Sequence diagram for read/write and recovery interactions

Experimental Procedure

The validation of the converter was
conducted under controlled conditions within the Microgrid Laboratory at the
University of Cuenca. The objective of this procedure was to demonstrate that the implemented converter facilitated reliable
and transparent communication between the SCADA system and
the Sunny Island inverter, which natively employs the proprietary SMA Data
protocol.

The validation process was initiated
by powering on the system and observing the automatic initialization of the services embedded
in the Raspberry Pi. These services included the YASDISHELL application for communication with the inverter and the Modbus TCP server.
After initialization, the SCADA client endeavored
to establish a Modbus TCP connection. Upon successful connection, the system initiated
a polling cycle of the Modbus registers
exposed by the converter to
retrieve inverter data.

The primary variables that were
monitored during the experimental phase included inverter output voltage and
current, battery voltage and state of charge, instantaneous power, and internal
device temperature. The selection of these parameters was informed by their
demonstrated relevance in operational monitoring and safety assessment in
isolated or hybrid microgrid environments.

To
assess the writing
capabilities of the system, specific
parameters were modified
from the SCADA interface. These
parameters included the maximum charge current and the minimum battery temperature required for restart.
Subsequently, the updated
values were verified
against the inverter's internal
status indicators to ascertain the correct implementation of the alterations. This process necessitated meticulous timing, as the system's architecture incorporates a minor delay due to its polling-based data
acquisition loop and asynchronous file-based inter-process communication.

To assess system robustness, the
physical connection between the inverter and the Raspberry Pi was intentionally
interrupted and then reestablished. During the disruption, the behavior
of the converter was meticulously monitored. It was determined that the system had the capacity
to recover communication without the need for manual intervention on its own. This resilience is imperative for
real-world deployments, where intermittent connectivity or power fluctuations
are to be expected.

Results and Discussion

This section presents the
experimental results obtained during the deployment and validation of the communication converter developed to interface the SMA Sunny Island inverter
with a Modbus TCP-based
SCADA system. The evaluation concentrated on system initialization
behavior, real-time
data acquisition, parameter writing functionality, temporal performance, and robustness
under connection interruptions. The findings substantiate the operational
viability and reliability of the converter within a laboratory-scale microgrid
environment.

System Initialization and Service
Execution

The
initialization of the converter system
is a critical factor in ensuring continuous and autonomous operation within the SCADA-integrated microgrid.
To evaluate this aspect, the Raspberry Pi device
hosting the converter services was powered
on under standard
laboratory conditions. The
startup process was then observed in terms of duration and service activation.

The total startup time required for
the Raspberry Pi to fully boot and launch the two key services: the YASDISHELL
application and the Modbus TCP server. This process was approximately three minutes.
The duration encompasses the loading of the operating system and all
requisite network and USB subsystems, which are indispensable for serial
communication with the inverter and TCP communication with the SCADA client.

After the initialization of both
services, it was ascertained that they were operating in an active
state. This verified
the successful deployment of the services
as background processes utilizing system-level service
management. This automatic startup behavior is essential to guarantee system
availability without requiring manual intervention after power interruptions or planned
maintenance. As illustrated in Figures 4a and 4b, the confirmation messages verify the
successful activation of both services, thereby facilitating seamless
communication with the Sunny Island inverter and ensuring immediate
availability for Modbus TCP connections.

This automated service configuration
has been demonstrated to have a substantial impact on enhancing system
resilience. In the event of an unexpected power cycle or network disruption, the converter automatically restores its full functionality, ensuring minimal downtime
and continuous data acquisition for the SCADA platform.

Figure 4

Active status of services

a)  YASDISHELL application (inversor)

b)
Modbus TCP server.

Data Acquisition and SCADA Visualization

After the converter's full operational capacity
and the Modbus TCP server's
activation, the SCADA system
successfully established a connection and initiated data polling from the Sunny
Island inverter. The graphical interface, developed in LabVIEW, displayed
real-time measurements retrieved via the converter, confirming that the
protocol translation from SMA Data to Modbus was functioning as intended.

The SCADA dashboard exhibited grouped
data according to relevant categories, including inverter status, battery
information, power flow,
and external grid parameters. These values
were updated at ten-second intervals, and no communication failures were
detected during

the observation periods. As illustrated in Figure 5, the monitoring interface displays
real-time operational data in a clear and intuitive manner.

The inverter output voltage and
current, battery voltage and State of Charge (SOC), system frequency,
and instantaneous power were identified as the key variables to be monitored.
A direct comparison was made
between these values and the physical display on the inverter, revealing
complete agreement in terms of numerical consistency. For instance, the battery
system's overall health, measured in percentage (SOC) at 76%, and the auto-start
counter, which registered at 3, were both displayed
on both the inverter panel and the SCADA interface. These values served to substantiate the efficacy of the data mapping process
that was executed by the converter.

Figure 5

Monitoring
interface for the Sunny Island inverter (the Spanish language is in accordance
with the native language of the microgrid operators). Note: the figure reproduces the actual operator
HMI used by the microgrid staff (Spanish-language interface)

The ability to seamlessly visualize inverter data within the SCADA environment, without the
need for proprietary SMA software,
demonstrates the efficacy of the protocol conversion approach and its
suitability for integration into more extensive monitoring infrastructures.

Parameter Configuration from SCADA

Beyond data acquisition, the
converter was also evaluated for its ability to enable parameter configuration
of the Sunny Island inverter directly from the SCADA system. This functionality is essential for supervisory control
environments, where remote
reconfiguration is often
necessary to adapt to changing operational conditions or user-defined profiles.

The SCADA interface incorporated a
configuration menu that enabled users to view and, when authorized, modify
inverter parameters. The interface is presented in Figure 6, which
illustrates various editable
parameters, including maximum
charge current (InvChrgCurMax), battery restart
temperature (BatTmpStr), nominal grid current (GdCurNom), and generator auto- start count (GnAutoStr). These values were dynamically read from the Modbus Input Registers
maintained in the converter's memory and reflected any changes made at the source device level.

The writing process involved the
issuance of a command from the SCADA interface,
which was subsequently captured by the converter's Modbus TCP server. Subsequently, the server
transferred the write instruction into a shared
file, which was monitored by the YASDISHELL

application. Upon detecting a pending instruction, YASDISHELL parsed and applied the new
value using the appropriate command structure of the SMA Data protocol. Subsequently, the inverter processed the change
and updated its internal state.

The
efficacy of this configuration pathway
was validated by writing test values into the
parameters and subsequently verifying their application through both the SCADA interface and the inverter's onboard display. The round-trip time—defined as the interval between the issuance
of a SCADA command
and the confirmation of its value—exhibited variability depending on the system’s execution phase. If the converter was in a state of idleness, anticipating instruction, the
alteration was manifested within a time span of approximately 10 to 15 seconds. If the system was executing a read cycle at the
time that the write request was issued, the response time increased to between
15 and 30 seconds due to polling synchronization delays.

Figure 6

Configuration interface
for the Sunny Island inverter.
Note: the figure reproduces the actual
operator HMI used by the microgrid staff (Spanish-language interface).

This
performance reflects the polling-based nature
of the converter's architecture, where read and write operations are decoupled and synchronized through
shared files and conditional
execution. Despite this non-real-time behavior, the delays observed are
acceptable for the intended application, where
operational parameters evolve
on the order of seconds
or minutes, rather than
milliseconds.

Despite these timing variations, the
configuration mechanism proved to be consistent and reliable, enabling remote
parameter updates without interrupting the SCADA monitoring process. The
converter's dual read/write capability signifies its robustness and its
potential for full bidirectional integration within intelligent microgrid
management platforms.

Resilience and Recovery
Behavior

The reliability of a communication
converter in a SCADA-integrated microgrid is determined by more than just its steady-state performance; its ability to recover from disruptions
such as power loss, network disconnection, or interface instability is
also a critical factor. To assess this dimension, a series of tests was
conducted. In these tests, the connection between the Raspberry Pi gateway
and the inverter
was deliberately interrupted and later re-established under different
operational conditions.

In scenarios involving temporary
physical disconnection of the Speedwire interface or loss of Modbus TCP
communication, the system demonstrated self-recovery behavior. After the
restoration of the connection, the YASDISHELL process resumed data polling, and
the Modbus server continued to expose the updated values to the SCADA client.
During these transitions, no service crashes or data corruption events were
observed. The experimental procedure was executed
in the Microgrid Laboratory of the Universidad de Cuenca, employing a Sunny Island inverter
and a controlled battery bank. Tests were performed in normal operating
mode, with short-duration runs (5 minutes)
and modest load variations to verify communication stability and read/write
functionality of the gateway. The conditions under which the work was conducted
provided sufficient evidence of feasibility.
A concise summary of the
system's observed performance (based on 10 runs) is provided in Table 1.

Table 1

Summary of observed performance (laboratory testbed)

METRIC

OBSERVED VALUE (LAB)

MEASUREMENT NOTES

Boot time (Raspberry Pi +
services)

4 minutes (±1 minute)

Time from
power-on to YASDISHELL + Modbus server active

Write / round-trip (SCADA

→ converter → inverter → confirmation)

10 seconds (±5 seconds)

Depends on converter state (idle vs during active read cycle)

Polling interval (configured)

10 seconds

SCADA dashboard updated every 10 s in experiments

Furthermore, the file-based
interprocess communication approach utilized by the converter contributed to
its fault tolerance. Intermediate data and command buffers were preserved in temporary storage,allowing the system to resume its data flow from the last valid state without requiring complete
reinitialization or reconfiguration.

This resilience serves to
substantiate the converter's aptitude for incorporation into critical monitoring environments, where
communication disruptions are a recurring phenomenon. The ability of
microgrids to recover autonomously and continue operating without human
intervention is essential for minimizing downtime and ensuring continuous
visibility into microgrid performance.

Limitations

The primary constraints of this study
pertain to the scope of evaluation and the nature of the prototype. The experimental design
involved conducting tests
within a single
laboratory setting, eliminating the need of extensive campaigns across
multiple sites or under high operational load conditions. This methodological approach,
characterized by its restriction to a
single laboratory environment, naturally imposes limitations on the extent to which the obtained
performance results
can be extrapolated to other contexts. The present architecture relies on file-
based interprocess communication and polling, which introduces additional latency and may not scale efficiently. While the reported response times are adequate for monitoring and configuration,
they are not suitable for real-time control applications. However,
significant concerns remain regarding the security aspects of the system,
particularly about authentication, encryption,
and functional safety mechanisms. Additionally, the system does not
currently incorporate transactional guarantees for write operations, which is a
fundamental aspect of ensuring data integrity
and reliability. Furthermore, scalability tests and long-duration experiments, including those involving fault injection or stress conditions,
were not conducted.

Additionally, dependence on the
proprietary SMA Data protocol restricts portability and may pose compatibility
risks. A notable limitation of the study is the absence of a direct
comparison with commercial gateway solutions. Such a comparison would have
facilitated a more comprehensive
contextualization of the study's findings, particularly about the
approach’s strengths and weaknesses. These limitations are
consistent with the exploratory nature of this thesis and define the next steps
required for a production-ready deployment.

Conclusions and Future Work

This work demonstrates the successful
implementation of a communication converter that enables protocol translation between SMA Data and Modbus TCP, allowing for the seamless
integration of the SMA Sunny Island inverter into a Modbus-based SCADA
environment. The solution,
implemented on a Raspberry Pi, effectively addresses the discrepancy between
proprietary inverter communication protocols and standard industrial interfaces
utilized in supervisory systems.

Through experimental validation, the
converter demonstrated its capacity to reliably retrieve real-time operational
parameters from the inverter and expose them to the SCADA platform
using conventional Modbus input registers. Additionally, the system enabled parameter
configuration from the SCADA interface, with alterations accurately propagated to the inverter
via a regulated asynchronous mechanism. The observed response
times, ranging from 10 to 30
seconds depending on system state, were found to be acceptable for typical microgrid monitoring
and control applications.

The
converter also exhibited robust performance in the face of operational disturbances. The system's capacity for autonomous recovery
from power cycles and communication interruptions, as evidenced by the absence of data loss and the need for no of manual intervention,
is attributed to the integration of automatic service initialization
with resilient file-based communication mechanisms.

Subsequent endeavors will focus
on enhancing the converter's functionality to integrate
multiple SMA devices concurrently and to incorporate supplementary inverter
models that utilize different communication protocols. The enhancements will also aim to reduce
response times through optimized polling strategies and explore the
integration of publish/subscribe architectures, such as MQTT, for event-driven
data transmission.

Acknowledgements and Declarations

The authors would like to express
their gratitude to the Microgrid Laboratory at the Universidad de Cuenca and the Department of Electrical, Electronic, and Telecommunications
Engineering, which provided the laboratory and equipment for the development of
this work. This work is part of the thesis: “INTEGRACIÓN DE LOS
INVERSORES SUNNY ISLAND Y AMPERE SQUARE S AL SISTEMA
SCADA DEL LABORATORIO DE MICRO-RED DE LA
UNIVERSIDAD DE CUENCA”.

The authors declare equal contribution and sharing of authorship roles for this publication. The
authors declared that, in the preparation of this article, AI tools were used.

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