I have the addressing for the Moxa device from the manual, but can't get the values to show up in Ignition.

Attached is the screen shot of the manual, with the address I am trying to get.
What do I need to enter in the device configuration?

In the address map you will configure these as 32-bit Input Registers starting from modbus address 1.

Thank you that worked.

Any way to get the data to come in as float? Currently a temperature value of 75.3 degrees comes in as 753. I tried changing it from Int32 to Float, but that does not give me a value.

You'll have to apply scaling or an expression to the tag in the designer in that case. Designating it as a float in the modbus configuration assumes that the value is in IEEE floating point format, not just the correct value multiplied by some factor.