Thank you for your post
You can connect several PT104 units on the same computer at the same time, I would recommend having no more than 9 on the same PC. You will need to ensure you have the appropriate RS232 ports to connect them to, or USB to serial adaptors.
You can view a maximum of 16 channels at any one time in the graph and spreadsheet views but you can set up monitor groups to switch between different groups of sensors. The software will record all the channels, it just won't display them all at once if there are more than 16.
Hope this helps