Connect several devices to the same serial port, multiplexing technique

Hi all!

I'm doing the brainstorming thing, I need to multiplex my PC serial port in several remote serials ports that let me connect several SCADA devices.

The problem is that the SCADA device and the software of this device and the firmware do not support device ID,headers or similar. All designed to connect only one device for each serial port at the computer.

The only idea that I get is add some header to the data and then send it at the common serial and let to the remote Arduino decide if the packet id addressed to him print this data at the serial output, for the opposite way the Arduino picks the data add his local header and then print in the main serial.

Think in several devices connected via RS-485 and and several Arduinos connected to this BUS, We have other way to do this? to multiplex a serial port?

Best Regards Frank

What do you mean by 'serial port' - do you mean a DB9 connector carrying RS232? Is there really a constraint that you have to use that serial port at the PC and no other? What on the PC will be talking over that serial port? Have you considered more conventional solutions such as using a USB hub and separate USB-to-RS232 adapters for each device?

Hi Peter!

No that is the problem, the remote devices are not close to any computer so they are connected together using RS-485 as link. The problem is that any of them support the RS-485 addressing. I can't identify who is talking.

Best Regards !! Frank