SA9103C

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7.

Software flow

In an application in which all the registers must be accessed, the software loop

illustrated below can be implemented.

READ FREQUENCY COMMAND

DELAY OF 8 MAINS PERIODS

RECEIVE FREQUENCY

READ ACTIVE COMMAND

LOOP

DELAY OF 8 MAINS PERIODS

RECEIVE ACTIVE

READ REACTIVE COMMAND

DELAY OF 8 MAINS PERIODS

RECEIVE REACTIVE

READ VOLTAGE COMMAND

DELAY OF 8 MAINS PERIODS

RECEIVE VOLTAGE

The SA9103C integrated circuit transmits the register values only after completion

of the current measurement cycle (8 mains periods maximum).

The delay of 8 mains periods can be calculated from the period value of the

frequency returned by the initial read, and updated with each subsequent reading

of frequency.

Each successive read of the registers takes place regularly at intervals of 4 blocks

of 8 mains cycles. This time and the difference between successive energy register

values can be used to calculate power.

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