Modbus read program issue

Hi All,
I’m trying to read an input register on a modbus TCP device with ethernet IP ending .173, it is using port 502 as standard and I’m trying to read register 3022 however when I refresh after sending to to the T3-Nano (non-ESP32 version) fw 63.2

this is my coding which I send
120 PV1VOLT = 173MB_INPUTREG3022

which changes to this after a refresh

Is this something I am doing wrong? can I do it differently? or is it a limitation on the register number?