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.

  • \$\begingroup\$ Shopping (aka product recommendation) is off-topic. \$\endgroup\$
    – brhans
    Aug 13 '18 at 16:59
  • \$\begingroup\$ Your title says 'RS285'. It sounds as though you're just looking for an RS485 to RS232 converter. I've never used one but there are many available. \$\endgroup\$
    – Transistor
    Aug 13 '18 at 17:03
  • \$\begingroup\$ I'm not looking for a shopping recommendation I'm looking for how to convert the signal. \$\endgroup\$
    – Michael H.
    Aug 13 '18 at 18:41
  • \$\begingroup\$ @Michael, could you add a link to the datasheet of your sensor? \$\endgroup\$ Aug 13 '18 at 18:52
  • \$\begingroup\$ Oh - ok - my misunderstanding. So where exactly are you stuck in your design? Show us what you have so far. Your question as written just seems to be "Is there a way to xxxx?" - to which the answer in this case is simply "Yes, there is". \$\endgroup\$
    – brhans
    Aug 13 '18 at 19:01

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.

enter image description here

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.


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