Secure transfer of commands and data across long distances: 2 wire up to 20 km and powerline up to 4 km

Principle of decentralised, distributed intelligence with neuron node microcontrollers and no central computer. Open network with free bus topology: strang / tree / ring
Communication between the neuron nodes is activated by incidents using standardised network variables (SNVT). With a 48-bit recipient addressing system and confirmation of receipt
In the event of incorrect receipt, the telegram is sent several times (retries).
Data telegram: differential Manchester encoding process, with CRC error checking and modified CSMA collision detection.

The C3-PLT bus coupler with the PL-3150 Powerline Smart Transceiver works in dual-carrier frequency mode. In other words, after 2 retries the transceiver automatically changes the transfer frequency for telegram transmission from 132 kHz to 115 kHz in the CENELEC C and B bands, with a transmission speed of max. 5.4 kbit. The modulation of the data telegram to the carrier frequency takes place using the DPSK process. These relatively low frequencies require high resistance to interference, in comparison to the normally high transient interference signals.

Other security features include high transmission power with 1 A at 13 V and 1 ohm internal resistance, with high input impedance of 500 ohm at Umin 0.5 V.
In each C3-PLT bus coupler, up to twelve C3 I/O modules with digital input/output can be connected via the DIN rail bus.

Very long transmission distances – well over 20 km – can be achieved with a direct, shielded two-wire connection between two C3-PLT couplers.

The use of a 230/400 V network takes place via capacitive coupling of the data telegram via a C3 network coupler. The most direct possible network connection between sensor and actuator nodes is thereby recommended.
In practice, there have been very good experiences noted with long-distance power supply stub connections to deep wells, floodlight systems, and snow cannons.
Another exceptional feature is the well-functioning data transmission in a cable car system via the insulated support cable and earth.
For such specific cases, UNITRO provides a free set to build a test circuit.

 Link:  https://www.unitro.de/en/products/c3-series/