First of all you must choose Modbus RTU Extend Driver,
And you must adjust port like below,
After that you can select the registers what cind of you want,
4X=HR, 3X=IR, 0X=Coils and 1X=Discrete Input
And I must inform you, GMTCNT has din rail mounting thermostat with display. You can review the device from this link https://gmtcontrol.com/dijital-sicaklik-kontrol-cihazi/ .