3.3.3.1 PLC Transmission Circuit

In the main transmission branch, the transmission stage adapts the output signal with the filtering blocks controlled by the ASO signals. It also provides a DC component and provides protection for received disturbances (see Figure 3-10).

CAUTION: Before starting to transmit, make sure that the 12V power supply is applied and stable to avoid damaging the driver. So, the DC Input Connector must be connected and the shunt JP1 must be installed on J5.

Figure 3-10. PL460 Main Transmission Stage for FCC Band (Embedded PLC Driver) Schematic

Note: The LED D4 (TX Main), connected to ASI0 of the PL460 (not in Figure 3-10), lights up with every message transmitted on the main branch.

In the auxiliary transmission branch, the transmission stage adapts the EMIT signals and amplifies them. In the PL460-EK board (see Figure 3-11) it is composed of:

Driver: It adapts the EMIT signals to either control the amplifier or to be filtered by the next stage
Amplifier: A Class-D amplifier generating a square waveform from 0 to 12V
Bias and protection: It provides a DC component and provides protection from received disturbances

Figure 3-11. PL460 Auxiliary Transmission Stage (Discrete Components) Schematic

Note: The LED D11 (TX Aux) lights up with every message transmitted on the auxiliary branch.