I am very new to the world of automation and PLC. I am using a Schneider PM5320 to read some voltage and current values. I then want to take these values and send them to my Unitronics (USC-B10-R38) PLC. I am using Modbus/TCP communication protocol. I have set up the Modbus slave in Unilogics (Unistream) and I was able to read some registers, but the relevant register I wanted (L-N average Voltage) shows 0.
I used a generic Modbus tester to see if I could see these values. 
As shown above, the voltage value are stored in two registers namely 3036 and 3037. These values in the registers were correct and corresponded with the value shown on the meter.
For reference, I used Registers 1 to 3 to check if the PLC is actually "seeing" the registers and the values. As shown beloe here is the values as seen by die modbus tester:
And here is the register values as shown through Unilogics, Keep in mind there is a offset of one:
As seen above, the PLC is correctly seeing Registers 1 to 3 but is failing to correctly retrieve registers 3036 to 3038.
Why is this happening?