How do I wire the RS232-to-RS485 adapter between the Crestron processor and the Somfy transmitter?

On the RS232 side, from the processor, you connect tx from the processor to the rx on the adapter and rx on the processor side to tx on the adapter. Ground from the processor goes to ground on the adapter. On the RS485 side, you would wire the TX/RX+ from the adapter side, to the + on the Somfy transmitter and the TX/RX- from the adapter to the – on the Somfy transmitter. Although wiring RS485 ground is optional, it is recommended to connect ground from the adapter to ground on the device. The example image below shows how the wiring should look like between the adapter and the Somfy transmitter.