The USB-Module seems to be a pretty normal USB2Serial with a RS-485 driver. The TTL-to-RS485 module doesn't provide a schematic (at least I couldn't find one) so I tried to find out how it's wired from the photos.
R1 to R4 seems to be directly connected to DI, RO, RE and DE, so they're just for chip safety. C1 or C2 is the decoupling capacitor for the MAX485. R8 is probably the current limiting resistor for the LED. I don't know where the LED is connected to and what the second capacitor is used for. I also cannot find out what connects to resistors R5 to R7. Can you try to find that out?