Monitoring of photovoltaic strings

Maximise your facility's profitability by monitoring the generation of your photovoltaic panels and tracking any issues that might occur.

Climate change and global warming are already a reality, and the only option we have to change this situation is to use efficient and sustainable energies that will keep our planet habitable for future generations.

It is no longer just about promoting renewable energies, but also about getting the maximum efficiency from this power source. As a result, we need systems that are capable of permanently monitoring, running and managing installations, and of interacting with all their components to ensure optimal performance.

A complete solution requires integrating STM systems into the Combiner Box, including all the elements associated with the protection of the strings, fuses, the output switch and the necessary overvoltage protections.

Data monitoring

Constant analysis of strings

Ensure the maximum performance of your photovoltaic plant by installing STM devices that are capable of analyzing and managing the electrical parameters and operating alarms of the photovoltaic strings in real time, and are adaptable to any type of installation.


Analysis of wireless coverage

Circutor can help you conduct a coverage analysis for STM devices with LoRa wireless communications to ensure that the data obtained from the monitoring system reaches the management centre.

DLM recarga VE fotovoltaica

The goal is to maximise the energy efficiency of photovoltaic plants.

In order to obtain reliable information on the operation of each string, the operator of a photovoltaic plant has to be able to receive real-time information on the status of the electrical parameters. This ensures both the efficiency of the photovoltaic generation, and that the operator will be informed of any alarms or problems that may affect the proper operation of each string line.

Optimised performance

What solutions can I install to ensure the performance of each photovoltaic string?

To make sure that each photovoltaic string is properly managed, CIRCUTOR offers its STM solution, specifically designed to continuously monitor photovoltaic strings, track the installation’s performance, and inform the plant manager of any alarms or problems that might affect the proper operation of each string line.

Its modular installation yields significant cost reductions in the design of combiner boxes, and makes it possible to connect the STM-S measurement modules anywhere in the panel, saving both space and cost, whether through Hall effect transformers, which avoids interrupting the measurement circuit, or using shunts, which provides the best measurement accuracy.


LoRa wireless communications for photovoltaic plant monitoring systems

Another relevant aspect to help minimise the investment is the proper choice of communication systems between the various photovoltaic arrays and the control centre. In installations with a large surface area, the laying of communications lines should be avoided, since it increases the cost of the solution and hinders maintenance work during connectivity outages. The best way around this problem is to use wireless technologies, such as the LoRa system. This type of communication uses a long-distance wireless data transmission technology (15 km) that, combined with string monitoring, is the most efficient communication system on the market.

In newly-built installations, the conduits already in place can be used to install STM equipment with RS-485 communications, using the infrastructure of the plant proper to connect the monitoring and control system to the management centre directly to the physical communications network.

String monitoring


Master device to provide the voltage reference, power the STM-S slave modules and provide communications to the STM system via LoRA wireless communications.


Master device to provide the voltage reference, power the STM-S slave modules and provide communications to the STM system via RS-485 wired communications.


4-channel slave module for measuring string currents. Direct measurement via shunt of up to 25 A DC, expandable to up to 8 devices (32 channels).


Slave module for measuring up to 16 current channels with Hall effect transformers (up to four trays with 4 or 8 100A transformers).

Circutor services

Analysis of the coverage of wireless LoRa communications

To determine the number of gateways (units that link SCADA and the Combiner Boxes) needed to cover wireless communications, the first step involves a

Ground Mapping process in the PV plant. This is a theoretical analysis of the LoRa communications coverage using computer tools that simulate the propagation of this type of signal. This study, done by Circutor specialists, yields a map of the terrain that shows the exact position of each Combiner Box in red, and the coverage level of the LoRa signal.

Once the installation points of each Combiner Box are determined, graphs are made showing the boxes and the inverters to verify the coverage points of the LoRa signal and decide if the communications between them will be adequate, or if there will be a coverage problem. The results of this analysis will depend largely on the layout of the terrain and, to a lesser extent, on the distances.

If the theoretical result is not entirely satisfactory, as might happen in plants with very complex terrain, Circutor offers a start-up service where specialist technicians travel to the facility to conduct RF tests and measurements in order to determine where exactly to install the various LoRa Gateways and ensure proper communications between the monitoring system and the management centre.