RS-232/RS-485 Communication

Adithya Ravichandran

Other Parts Discussed in Thread: TMS320F28335

I am trying to embed the TMS320F28335 control card in a power converter, and use the SCI communication interface. Upon examining the control card schematic, an onboard RS-232 chip connects the transmit and receive signals. I need to use RS-485 for my application. Do I need to use an RS-232 to 485 converter or can I directly connect the Tx and Rx signals to the RS-485 IC?

Thanks!

-Adithya

over 13 years ago

0 Manoj Santha Mohan over 13 years ago

TI__Guru 55700 points

No, you need to use RS-232 to RS-485 converter.

-Manoj

0 Adithya Ravichandran over 13 years ago in reply to Manoj Santha Mohan

Prodigy 140 points

Do you know of any IC's that convert between RS-232 and RS-485?

0 Mikael Andersson over 13 years ago in reply to Adithya Ravichandran

Prodigy 240 points

I use the F28027 control card. On that, the SCI signals are available on the docking station (as well as the RS232 signals). Unless the GPIO are only able to drive one IC there should be no problem to attach a RS485 driver parallell with the RS232 driver. The output from the RS232 driver (RX signal) even has a 0 ohm resistor that can be unsoldered so the driver outputs dont collide.

I suggest you study the controlCARD and docking station schematics to see if the same thing is possible for your CPU.

Happy hacking,

/Mikael

C2000™︎ microcontrollers

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RS-232/RS-485 Communication