The TX Disable pin is used to drive the external TX Amplifier. When the transmit circuitry has a much lower impedance than the receive circuitry. If the Amplifier is not disabled, the chip will not be able to receive any signal from the powerline.
Even if you switch off the buffer, it will not shut down the TX Amplifier. Also, the code that controls the TX Disable pin is a part of the PLT User Module library and cannot be modified.
Could you create a support case and attach the your schematic to that? It will be much easier to help with these issues if I know your circuit better.
Let me know if you need anything else.
Applications Engineer - PLC
I am working on PLC CY8CPLC20 28PVXI. I am trying to transmit data using main.c code example given in PLT datasheet.
But transmitter is not working. There is some FSK signal at tx pin of IC, when I checked with oscilloscope. But tx_disable pin is always high. It is disabling ampification stage in power line coupling circuitary. So full transmission is not happening.
Why tx_disable is always high when I checked on oscilloscope?
thanks & regards,
code1.txt.zip 755 bytes