## 4 Conclusions  
In this work, a novel distributed synchronism system based on the Time-Sensitive Networking (TSN) standard has been validated for its integration in an architecture oriented towards the high-resolution digitisation of photovoltaic generation systems. Experimental results and statistical analysis show that it is possible to deploy a distributed acquisition system with a synchronism level lower than 1 us. The system was specially designed for a photovoltaic plant with a modified uPMU that would act as a TSN master and as a centralised capture system based on DAQmx technology. To compare the 2012 technology with the current one, the results obtained with the PTP technology applied to smart grids can be analysed [9]; it is a publication of the (PAIDI-TIC-240) research group of the University of Cordoba in 2013. With PTP synchronism technology for cKIOs, the manufacturer guaranteed a distributed synchronism of up to 1 ms. The tests published by the group estimated levels close to 75 us. This paper analysed the results with different levels of network traffic. The current methodology was not analysed with this type of conditioning because the standard establishes a traffic-independent method as a basis. It is currently possible to combine PTP and TSN in the same cRIO-9054 chassis to synchronise devices with both technologies independently. This is an alternative that will be explored to combine critical systems that need a higher level, such as PMUs and other ancillary capture systems with less stringent standards but that require at least 1 ms of a clock coordination level. Such lower-cost capture systems would ensure much better time-stamping than NTP. The results obtained in the laboratory with a configuration similar to the one to be used in photovoltaics were of very good quality. With the NI-9215 with four chassis, a guaranteed response of 100 ns was obtained for an uncertainty of 5%. In the plant, the separation between the transformation centres CT1 and CT2, and the transformation centres CT3 and CT4 was 150 m. The IEEE 802.3 standard for structured UTP Category 6 cabling recommends a maximum link length of 100 m. The ideal solution to obtain very similar results is to add a TSN compatible switch at an intermediate point to link two 75 m conductors. Future work will compare this alternative with the use of a 150 m cable, which is at the permitted limit but not recommended. In comparing the test results in Table 5 with those in Table 8, the response with 75 m and 50 m cables in some of the configurations outperforms the results with cable lengths of 2 m and 10 m. This is because three factors played a role: a more advanced ASUS 100/1000 MB router with a higher transfer rate, category 6 cables with higher bandwidth, and a firmware upgrade of the cDAQs were used in the second phase. Additionally, it has been verified according to the results in Tables 7 and 8 that for the measurements of distribution network voltages, it is essential to use high-quality resistive dividers instead of active transducers such as the LEM LV-25. Dividers with very low-temperature coefficients and very high impedances guarantee measurement quality and long-term stability. Future work will analyse the level of synchronism that can be achieved for simultaneous measurements of power quality parameters with measurements from a grid of 32 irradiance sensors distributed throughout the PV plant and connected to the cDAQs with four NI-9203 modules with eight current loop inputs. Another major challenge concerns the creation of a local database with a time resolution of at least 3 s to allow for a predictive analysis of the evolution of the power generation of the plant depending on the passage of clouds. The same database would include the phasor information from the \(\upmu\)PMU, which acts as the main source of synchronism and collects data on both the quality of the supply and the 32 irradiance measurements.