Hi, this is not SIEMENS related question. It's a general question regarding plc programming.

I am giving out and receiving some data from SIEMENS PLC to some other brand of PLC. From SIEMENS, there are some 4-byte data, mostly 8-byte data and they are all configured in transfer slot. 

However, when I transferred to that PLC, it got mapped to 1 byte size data, SINT. It's fixed, I cannot change the data type.

For example, from SIEMENS, I gave out a REAL (4-byte) data, which has a value of 3666.6. But in the other PLC, it got mapped to 4 SINT values.

Module001_VSM_2_1003001 = 69

Module001_VSM_2_1003002 = 101

Module001_VSM_2_1003003 = 41

Module001_VSM_2_1003004 = 154

How do I combine all these SINT values to become one REAL value in LAD or SCL?

Alani Zulkifli

It's a general question regarding plc programming.

Actually general answer most possibly won't help you directly.

You have 4 bytes (8 bits chunks) which should be combined into one 32-bit chunk (DWORD) which then should be interpreted as REAL.

And here comes PLC vendor specific answer.

In S7-1200/1500 you can use the LGF library. First you change type of received data to BYTE in network IO configuration, because with SINTs it's overkill, then you use LGF_MergeBytesToDWord and finally you convert DWORD to REAL. Done.