Converting WORD High and Low to separate UINT in EcoStruxure Operator Terminal Expert

[Tobias_84]

I'm adding a HMI to an older control unit. It uses MODBUS RTU as communication.

The problem I'm facing is that the information from the control unit is mixed as USINT(8), WORD(16) and also some DWORD(32). I need to be able to read and write new data to the control unit.

I have tried to use the Converters and Expressions function but could not make it work.

As example:

%MW1000: High USINT(Var1), Low USINT(Var2).

%MW1001: High USINT(Var3), Low WORD(Var4)

%MW1002: High WORD(Var4), Low WORD(Var5).

%MW1003: High WORD(Var5) Low USINT(Var6).

%MW1004: High USINT(Var7), Low USINT(Var8).

I have made this work before, but I did the conversion on the PLC, (M241), but this time no PLC is used.

Any Ideas to do it in the HMI? (HMIST6400)

Can a script be used?