Ah! Thank you! Now i understand! But it didnt make any progress... only 0 values...

Is there some way to see that the communication between logo and module is correct?

Hi,

the register you want to read is a DWord.

When you are in online test, open the datatable and add VD0:

LOGO! it selve only support signed integer, but not DWord dataformat.

Hope this helps

The first problem is a false ip address in your Logo program for Modbus server. The ip address should be 192.168.0.121 (QModMaster), but in Logo you have 198.168.0.121.

The second problem may be the data type. Logo only knows 16 bit signed integer (-32768 ... +32767). Your values have 4 bytes = 32 bit signed or unsigned integer. Try to find float values in the Modbus table, these you can convert in the Logo to 16 bit signed integer, but depending on the value you will loose some decimals.

Regards, Scorp

Hi,

you are right. A LOGO! only support signed integer.

But if you read or write a DW or Float to LOGO! into V-Memory (via ModbusTCP or S7), then you can "see" it in the Online test data table. Open the table and ad VDx. You also can see a float value.

The memory in LOGO! can be used to forward such values to AWS, Simatic, ..... But LOGO! can not use the values outside the signed integer range in the program. Except the F/I and I/F. But this two instructions only "transfer" unsupported dataformat into signed integer.