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? 

[Cade_Shipek]

You can read bytes in OTE/BLUE by creating a Variable with array size 2 of type USINT or any BYTE type. It will assign the correct address to the low and high bytes.

[ismailozinan]

Hi,

HMI can swap all of high and low section of register while it is reading or writing. It is enough what is base of variables? as attached file. If HMI uses internal variables without plc, in this case we can use attached script.