I successfully adopted your Modbus OS program on my DMG10600T070_A5WTR.
But I can't find the way how the HMI(DMG10600T070) automatically shows new screen(page no. 005) when STM32 saves screen number(ex. 005) to 0x100H(modbus address).
1. STM32(Modbus slave/PLC) change data at the address 0x100H.
2. HMI(DMG) recognizes it, reads the data at SMT32(Modbus slave/PLC), and saves the value at HMI's VP(ex 0x5000H).
3. HMI change the screen number to 005.
4. Clear 0x5000H data
5. Send current screen number to STM32 address 0x102H.