Data acquisition system

A data acquisition system (DAS) gathers performance data from PV plant equipment, mainly inverters, and usually does this through a data logger. In the usual data chain, the inverter measures DC and AC values and keeps them in internal registers. A data logger then sends them to a database, a vendor portal or a third-party monitoring site. The logger can pass values through unchanged, average a set of samples, or keep one sampled value per interval. So the data in the database may not match what the inverter sent. In one documented plant, the datalogger sampled six inverters every 2 seconds and stored only 10-minute averages. Typical DAS maintenance includes checking power supply voltages and comparing current transducer and sensor readings against calibrated instruments, which shows up sensor calibration errors. DAS plans are often missing or lack detail. If the DAS uses the building IT network, network upgrades or routine IT maintenance can cause connectivity problems. Large central inverters provide a dedicated connection for a third-party DAS. The related term SCADA stands for supervisory control and data acquisition.

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• sentence 7: support check: partial - The SCADA expansion is supported. The titles of u5 and u6 only name a third-party DAS connection, so they do not say that large central inverters provide a dedicated one.
• sentence 7: review: partial - The SCADA expansion is supported, but the Yaskawa section headings only name a third-party DAS connection and do not say that large central inverters in general provide a dedicated one. -->