Hi, I am able to read a file and make a string from that. But the read action is only happening once so that the string stays constant. I want the the string to be updated after every one second.
This is the code,
VAR sFileName : FILE.CAA.FILENAME; FileOpen : File.Open; FileClose : File.Close; FileRead : File.Read; iState : UINT; hfile : FILE.CAA.HANDLE; sReadLine : STRING(1000); END_VAR VAR_INPUT xInit : BOOL; END_VAR VAR_OUTPUT xError : BOOL; xDone : BOOL; END_VAR CASE iState OF 0: sFileName := '/sys/bus/w1/devices/28-44260f1e64ff/w1_slave'; xDone := FALSE; xError := FALSE; iState:= 3; 3: // Open the file with read access. FileOpen(xExecute:= TRUE, sFileName:= sFileName, xExclusive:= FALSE, eFileMode:= File.MODE.MREAD); IF FileOpen.xDone = TRUE THEN hfile := FileOpen.hFile; FileOpen(xExecute:= FALSE); iState := 4; ELSIF FileOpen.xError = TRUE THEN iState:= 32767; FileOpen(xExecute:= FALSE); END_IF 4: // Read the string from the file. FileRead(xExecute:= TRUE, hFile:= hfile, pBuffer:= ADR(sReadLine), szBuffer:= SIZEOF(sReadLine)); IF FileRead.xDone = TRUE THEN iState := 5; // Cut off the unused characters. //sReadLine := MID(sReadLine, ANY_TO_INT(FileRead.szSize), 1); FileRead(xExecute:= FALSE); ELSIF FileRead.xError = TRUE THEN iState:= 32767; FileRead(xExecute:= FALSE); END_IF 5: // Close that file. FileClose(xExecute:= TRUE, hFile:= hfile); IF FileClose.xDone = TRUE THEN iState:= 6; FileClose(xExecute:= FALSE); ELSIF FileClose.xError = TRUE THEN iState:= 32767; FileClose(xExecute:= FALSE); END_IF END_CASE
I would be super happy if someone can guide me
Could'nt you just change this line :
iState:= 6;
To :
iState:= 0;
So your state machine goes back to state 0 and it loops infinitely ? If you want to time it you can just add a wait state with a timer.
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Hi, I am able to read a file and make a string from that. But the read action is only happening once so that the string stays constant.
I want the the string to be updated after every one second.
This is the code,
I would be super happy if someone can guide me
Last edit: master-student 2022-06-30
Could'nt you just change this line :
iState:= 6;To :
iState:= 0;So your state machine goes back to state 0 and it loops infinitely ? If you want to time it you can just add a wait state with a timer.