I have never tried this before. I need two systems to talk to one device. I know RS232 is a one to one communication, but can I hook two processors to one device?

Thinking this through if either processor sent a command to the device it should respond, and could have the processors ignore commands from other processor, so I think it would work.

I found this on line.

[Link: blackbox.com]

I also found this on another site when researching, and this should work because one processor is needed for control of the device, and the other just needs to read feedback from the device, no control.


You can connect one output to multiple inputs, but you cannot connect multiple outputs to one input.

That means you can connect the line that transmits data from your scales to the PC to a second PC, but you cannot connect the two lines that transmit data from the PCs to the scales.

So yes, you can "tap in" to the transmitted data, as long as you only want to read the data.

i believe it was/is Kramer that made a device that would connect multiple RS232 controllers to a single device.  I actually have one in a box in my garage that I briefly tested out.  I can look at it this evening to find the model number.

This was never the intent of RS-232, but allowing two receivers to monitor the same send line is OK as long as they don't overload the send line. It's up to your programming to figure out what to do with the data.

If you dig through the Wikipedia article, you'll get a notion of the voltage levels that you might discover. As long as the send line voltages are within the range that your receiver can deal with, you'll be fine.

here is the product that I thought would work for you

[Link: kramerav.com]