Data Link Layer

The data link layer manages the logical link between sender and receiver. Its primary tasks are station addressing and error detection.

The DNP3 driver uses the FT3 format. This means that every octet is enlarged by a start bit and a stop bit (a 16 bit CRC is used), by what a asynchronous data communication is possible.

In addition, the data link layer uses only the balanced (symmetrical) communication.

Requests and responses in a multidrop topology may cause a certain time delay.

Using the multidrop topology the "Collision Avoidance" is realized through different access times on the bus.