RSLogix 5000 STOD command

bernie_carlton · Feb 28, 2013

What occurs if a string which has no numbers in it is given as the source? Does the destination change at all? I don't have a system here to test on.

I see that the Knowledgebase says the destination is not changed if an empty string is present. I'm wondering if the same is true with a non-empty string with no numbers is presented.

bernie_carlton · Feb 28, 2013

I got the answer from Rockwell first (didn't know it was a race?). The action is as if it were an empty string, the destination is not affected.

jkerekes · Feb 28, 2013

Well, I just tried it in 5000 emulator, and it makes the Dint a zero, overwriting what's there. I don't know if the emulator handles this differently.

bernie_carlton · Feb 28, 2013

Thanks for that. I guess Rockwell advice needs an update. For my particular problem the result yields the same effects. But I would think that logically it should do nothing to the destination as there would be no numeric information available (not even a zero).

dmargineau · Feb 28, 2013

L61 Rev.19 CPU
STODing an "empty" string ('') does not modify the DINT destination.
STODing a "zero" string ('0') will "zero" the DINT destination.

jkerekes · Feb 28, 2013

Yes that is what happens. But I thought the question is what happens if the string has no numbers in it, just letters. In that case, the dint is overwritten.

dmargineau · Feb 28, 2013

It is handled similar to the Emulator.
A "strictly ASCII" STODed string will "zero" the DINT destination.

RSLogix 5000 STOD command

bernie_carlton

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