ABSTRACT
The concept of autonomous PV monitoring systems consisting of many low-cost self-contained specialized functional modules based either on 8-bit PIC (RISC type) or AT89C52 family microcontrollers is presented. Each of the PV data acquisition modules (PVDA-Modules) has been designed and programmed for specified application using the concept of EOP (Event Oriented Programming). All types of modules may communicate with PC in both directions via RS485 bus. Since each PVDA-Module may be accessed only by its own unique two character address so there is no practical limit for the type and number of used modules and monitoring system may be easily expanded and/or modified when necessary. PVDA-Module starts transmission of gathered data, e.g. values of integrals, only after receiving properly addressed request from the PC, otherwise command is ignored. After initialization by PC computer PVDA-Modules can work autonomously and collect data over the 3-4 months period. Software for control of PVDAS-Modules may be easily written in any programming language in either MSDOS® or MSWindows® environment (e.g. Borland's Pascal, C, C++, MS Visual C++) or using specialized visual environments like NI Lab View®, HP Vee® or TestPoint®. More detailed description of the IVModule-A designed specifically for monitoring PV modules and/or arrays is presented.
