Simple digital power measuring system with Single Phase Energy Metering IC (AD775X)

• Program in PIC16F84A CMOS processor (4 MHz)
• Siple frequency ->> serial data stream conversion
• 8 paralell frequency input channel from AD775X's
• Serial data out 4800 / 9600 baud for RS485
• DIP switch's for selectable data speed and modul address (4800/9600, 0 - 127)
• 12 bit resolution
• Tolerance < 1% (6 - 800 W)
• Measuring start input from PC (reset)
• Send data enable input from pevious modul
• Data transmission ended output for next modul
• Max. 25 sec conversion time
• Cascadable up to 128

Data output stream contant :

8 x 2 bytes power data (P[i]=k / data[i])
2 byte's total measuring cicle's
1 byte modul address
1 byte error checking for 8 channel

Simlified Shema