Re: Monitoring RS485

I have used a home made device, along the lines of Fred's description,
to do exactly what you are asking. The device tapped off of the rs-485
lines with a cmos inverter and then fed the inverter output to a rs232
driver. Jumpers were used to select one or two inversions as
necessary. using two of the devices, and a program I haven't been able
to locate (though I wish I could - it was called something along the
lines of datascope or pals), I could monitor both the recieve and
transmit channels simultaneously.

I would imagine that there are commercially available tools available
for this purpose, but I have no idea how much they would cost, but
probably a lot. You could probably make up your own circuit easilly
enough, but then you would still need to find a monitoring program.

.