WagoAppSiemensS7Protocol

CODESYS
1

Has anyone used this library/ function in Codesys?
I can add the library and initialize the function block but nothing happens when running the software.
The trigger is not reset, no status given, no error, no busy, …

I’ve set up a S7-read block in Node-RED just to make sure that everything is set on the Siemens-side and it works.

db25_1
db25_1471×282 7.1 KB

db25_status
db25_status1145×153 4.42 KB

db25_trig
db25_trig772×101 3.78 KB

2

Hello bjornidar,
as there is no active connection in your screenshot (see xConnected), the xTrigger is probably not handled any further. Please note that the put and get function must be activated, unfortunately I can’t tell you how to do this in Note-Red. With a 1500 or 300 Siemens controller, it works for me without any problems. I would therefore first concentrate on making sure that you have an active connection.

image
image490×122 4.14 KB

3

Cannot believe it took me this long to realize I didn’t call the action/ sub-function :exploding_head:

Thanks for the reply anyway!

4

Have you been able to write to S7 with type “REAL” (8)?
The function block “Fb_DB_ReadWrite” returns xError no matter what I try when writing to the Siemens PLC.

I’ve successfully read/ written BYTE, WORD and DWORD but for REAL-values I am only able to READ.

5

you have to use conversion functions from library, check application note WAGO Global | 15941

6

Yes, I’ve tried that - both versions of the converter but still get “WriteCommandFailed”, “Error”, “uiID 1”.

Do you have a program example where you write REAL values?

7

Does anyone have an example program with REAL-writes to a S7-PLC? I’ve now got both a S7-300 and S7-1500 on the bench for testing, and cannot get the REAL-writes to work.

s7DB(
	xOpen:= xStart, 
	sIP:= strIP, 
	wDB_Number:= wDB_Num, 
	bType:= bType, 
	wOffset:= wStartAddr, 
	wCount:= wNumRegs, 
	pWriteData:= ADR(arrWriteData), 
	xWriteDB:= xWrite, 
	bTsap:= 0, 
	xTrigger:= xTrigS7, 
	aReadData:= arrReadData, 
	xConnected=> xConnected, 
	xDone=> xDone, 
	xError=> xError, 
	oStatus=> );

FOR bLoop := 0 TO bNumregs - 1 DO
	arrReal := Fu_DB_REAL_WRITE_CoDeSys_TO_S7_2(rIn:=awWriteReal[bLoop]);
	
	
	arrWriteData[bLoop*4] := arrReal[0];
	arrWriteData[(bLoop*4)+1] := arrReal[1];
	arrWriteData[(bLoop*4)+2] := arrReal[2];
	arrWriteData[(bLoop*4)+3] := arrReal[3];

	(*conv.rRealValue := awWriteReal[bLoop];
	arrReal[3] := conv.byteArr[0];
	arrReal[2] := conv.byteArr[1];
	arrReal[1] := conv.byteArr[2];
	arrReal[0] := conv.byteArr[3];
	arrWriteData[bLoop*4] := arrReal[3];
	arrWriteData[(bLoop*4)+1] := arrReal[2];
	arrWriteData[(bLoop*4)+2] := arrReal[1];
	arrWriteData[(bLoop*4)+3] := arrReal[0];
	*)
END_FOR
8

Hi,

have you tried to handle real as dword as in the example of the documentation tab as workaround?

Example 3: Write 2 real to DB7.DBD0 and DB7.DBD4

-wDB_Number=7

-bType=6 (handle real like dword)

-wOffset=0

-wCount=2

-xWriteDB=TRUE

The data which should be written has to be placed at the input pWriteData=adr(WriteData) (WriteData:ARRAY[0..1] OF REAL). Please use Fu_DB_REAL_WRITE_CoDeSys_TO_S7 to convert the real variable: WriteData[0]:= Fu_DB_REAL_WRITE_CoDeSys_TO_S7(myReal1) WriteData[1]:= Fu_DB_REAL_WRITE_CoDeSys_TO_S7(myReal2)
9

No, I missed this part in the docs but this seems to work just fine :+1:

Thank you!