I've been trying to get around an issue in Plc DataArithm blocks with strings or time values -
although accessing integer and floating point arrays (IArray500,AArray500, etc) works fine - like this:



Trying the same sort of access to an Sv's ActualValue halts the Plc thread (even just a read access), for example:



The same result occurs for any access to a ATv ActualValue, read or write

Note that locally declared pwr_tTime and pwr_tString[80] storage causes no issues. But can't be used in an object...

Any clues for me, folks? What am I missing??

Hi Bruce,

It's obvious, but maybe add include <string.h>

Otherwise, try CArithm

/Bruno

#include <string.h> didn't change things at all - and I've tried as a test just to access a single character in a string (Sv object source).

Even simplifying down to

classdef Da2 Sv;
char *s;
s = Da2->ActualValue ;
OI1 = s[0];

...causes the Plc thread to halt. I'm guessing it's a segmentation fault issue. Is there any way in ProviewR to see what caused a Plc thread to crash??

Hi Bruce,

Read this

/Claes

That's the key! Thanks! All works now...

I see that an SArray[100] does NOT use gdh_TranslateRtdbPointer() - is there some general way to tell what items need translation and what don't??

I suppose if one way crashes, do it the other way...