Jul 21, 2008 · XIC vs. XIO When hardwiring you always use a normally closed pushbutton when you wire in a stop for obvious reasons. When you wire into a PLC you always have to think about safety of course and also the programs ability to update when something happens in the process.

May 15, 2003 · XIO & XIC are terms relative to the way an input is treated within the ladder...ie how software can act upon the fact of the input being on or off with latitude in how you use the features. It allows more versatility then hardwiring, you get …

Jan 15, 2005 · XIO XIC - CONFUSION - CLARIFY - THANKS MANY THANKS to Terry Woods for explaining history of XIC and XIO. I am just learning PLCs and I have 1. Found this very confusing 2. STILL confusing 3. Can be dangerous if wrong instruction is used. 4. Will always test to ensure I …

Mar 27, 2025 · XIC, XIO, Greater than, less than, Equal, Not Equal are examples of input instructions. These are considered Non-destructive as they only look at a value, without affecting the value. In Rockwell Logix style controllers you can cross-reference a tag and it will show you all destructive and non destructive occurrences for that tag.

Mar 27, 2025 · An XIC and XIO are simply instructions that evaluate a memory bit is true or false. This isnt quantum computing, so that memory bit will ALWAYS be either true or false. There is NEVER an instance where the memory is neither False or True or both False and True.

Mar 13, 2003 · While working with ladder logic inside the PLC program itself, it is probably better to NOT think of your XIO and XIC as N.O. and N.C. contacts. Rather, think of them as "Active High" and "Active Low". For instance: A flag in your program (M3.1) is currently not satisfied.

Jul 20, 2009 · Whether you use an XIC (Examine if Closed) or XIO (Examine if Open) depends on what you want your PLC Code to do. If you want the Limit Switch to trigger an action, you would normally use an XIC (i.e. Turn on a Pilot Light). If you want it to stop an action, you would normally use an XIO (i.e. Stop a Carriage).

May 14, 2003 · XIC (or the corresponding symbol, regardless of brand) is an INSTRUCTION, not a contact. It instructs the processor to check the state of a bit in memory - looking for a 'one'. When I was learning PLC, I actually taught myself to refer to the XIC as the "look for a one" instruction. XIO is...

Jun 12, 2005 · XIC and XIO: For you newer PLC programmers, if you get it clear in your mind about how the two common digital input commands work, (XIC and XIO for Allen-Bradley RSLogix users), then you will be well ahead of the learning curve. There are at least 8 possibilities, if you consider whether the physical device circuit power is on or off.

May 14, 2003 · All sorts of games can be played with the XIC/XIO question, since the PLC asks the question anew each time the instruction is encountered. If logic exists to change the value of the register (even a direct input) for the part of the scan prior to asking the question, then the answer will be different than it was before the change was made.