I need to connect a sensor that uses a RS485 transmission to RS232 or something I can read through the com ports on my data logger. I can't use usb ports or virtual com ports due to the program I am required to use not accepting data through usb in any form. Is there a way to convert the RS485 to something I can input through the DB9 connection available on the computer? I am pretty new to data transmission in general.
There exists such conversion but it's not as simple as putting a cable with RS-232 standard male cable to a RS-485 standard female cable or vice versa. The RS-485 standard protocol is very similar to RS-232 in terms of serial communications. However, the RS-485 has Differential Signaling, which basically means that it transmits information using two complementary signals.
NOTE: The circuit diagram above is an example that can be found here of how this conversion may work. This could be one way you can differentiate a signal. As far as the materials you need, that's up for you to decide. If you're purchasing an adapter, I will not be able to provide recommendations. There are multiple ways to approach this problem, this is just one example.
Credit from Magnet Tech Research for the circuit diagram.