As far as I can tell, all the information you need is in the manual. It's actually pretty well written. I think perhaps you need to read a bit on the MODBUS protocol to understand what it means?
output mode. The default mode of the module is change output mode;
I'm not sure how you're getting data that at least looks valid with the wrong baud rate, but the device should be sending data out when something changes, so you don't even need to send it commands. The message protocol is on page 5, section 2 under "Slave Reply."
HTH