Make the given paragraph clearer.
Although the commons of each channel are isolated from power ground by the input-to-output isolation barrier, they are not isolated from each other. A common mode voltage on one will attempt to float all the others, sometimes with disastrous results.
Although the commons of each channel are isolated from power ground by the input-to-output isolation barrier, they are not isolated from each other. Therefore a common mode voltage on one will attempt to float all the others, sometimes with disastrous results.