Do you have a 4 channel scope with an RS-232 interface?
What scope are you using?
Typically, the scope uses RS-232 or GPIB for commands. That communications interface is not tied to one channel. Depending on the scope, there are commands to setup triggering, horizontal and vertical parameters, etc. To download data, there is typically a command to specify the data source (e.g. Channel 1, etc.), then another command to do a download.
Your scope can capture data on 4 channels at once (real-time), but you can only download one channel at a time (not real-time).
You need the command details in the programmer's manual for your scope.
