To configure them as GI/GO?
Is there a Rack number for RI/RO?
- Sergei Troizky
- Thread is Unresolved
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To my knowledge, no. I'd be interested in knowing if there is one though.
A workaround could be to have a background program move the state of the RI/RO to flags, then setup your GI/GO to the flags.
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I ended up interconnecting RIs to consecutive DOs and configured these DOs as GO.
Unfortunately, cannot do the same for ROs, as they are not subject to Interconnect.
BG logic is always an option, but it will execute by unpredictable chunks, and the result may appear not true realtime.
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Why would BG logic make "unpredictable chunks"?
I think BG Logic would work just fine. Especially if you run it in fast mode.
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This is what the manual says for the $MIX_LOGIC.$Item_count system variable.
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Your not going to get anywhere near the limit with just the RO's. BG logic will be reliable for this.
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According to the manual in "high-level mode" you are guaranteed to be able to execute 540 items in one scan. So if you had a A BG logic program like this:
: RO[1]=DO[1];
: RO[2]=DO[2];
: RO[3]=DO[3];
: RO[4]=DO[4];
: RO[5]=DO[5];
: RO[6]=DO[6];
: RO[7]=DO[7];
: RO[8]=DO[8];
That would only use 24 items of 540 allowed in High level mode. Even if you exceeded the 600 item limit of a normal BG logic program it will still work fine, it would just take 2x scan time to complete. I can say with 100% certainty that BG Logic works well and will not have any issues with this task. I have used it many times with a lot more items than this and it works perfectly.
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You're right, most of the times it will not be a problem.
In my current project, though, I have two (and probably will have the 3rd) BG programs in Normal mode and over 600 items total.There is an interesting question, though.
If a fragment of BG logic is skipped by jump instruction, does it count for the "number of items processed"?
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I don't think they count if jumped over. You can run an individual BG program in high level mode just for your RO and that will guarantee that it will be fine. Then keep your other BG seperate as it is.
I believe the 600 item limit is per BG program and you can have up to 8 of them.
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