Solution
The X310 motherboard includes four internal connection buses for RF daughterboards. While most daughterboards (such as UBX or CBX) require two buses each, the BasicTX and BasicRX boards only require one bus per unit. This allows for up to four BasicTX or BasicRX boards to be installed in a single X310.
However, due to internal bus allocation constraints, the configuration must include two transmit (TX) and two receive (RX) boards. It is not supported to install four TX or four RX boards exclusively.