How do the RS232-RS485 converters work?

Thread Starter


Joined Jun 8, 2014
Hello, I'm developing a project where 3 devices will either transmit or receive (NEVER at the same time), but the problem is that two of those devices have the RS232 protocol predefined (one of them is a PC, the other one is a scale). So I think my only option in order to communicate those 3 devices, is to use converters to RS485 (please correct me if I'm wrong), like these But I can´t find (I'm not a native english speaker, so probably I'm not using the right key words for the research) any information about the transmit enable bit (like the one in a MAX485). So that is worrying me because I don't know whether the peripherals are going to be talking/listening when I need them to.

Please!! Any info will be appreciated. Thank you!

(I'll use half-duplex, asynchronous mode)


Joined Jul 1, 2009
RS232C is a standard. You can look up the standard, or look on google, the format is widely known and understood. Trying using an RS232 chip that will convert TTL to RS232 (This includes the serial protocol and the differing voltage levels. It's simple to make your own TTL to RS232 I/F board like this one, I did:

Uses a MAXIM232CPE chip. 4-pin connection is TX, RCV, +5, GND