2003年5月14日 · The oppposite happens when you use an XIC with the N.C contact, it will be true. When you use a device like a Pushbutton with NO contacts as an XIC then it will be true when the Pushbutton is in its natural state..ie no signal to the plc. When you push the Pushbutton then it will be false in the ladder.

2003年3月13日 · Ex: a Normally Open Limit Switch is connected to input one on the PLC module. If we want an output or an internal bit activated when the limit switch pushes close, then in the program an examine on bit is used for the limit switch I:0/1 this address or whatnact is connected to the icon that looks like two backward brackets with no line through it.

2008年7月21日 · 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 …

2025年3月27日 · The fundamental operation of ANY PLC would be that an XIO/XIC pair would evaluate the same. A single bit will only be true or false when evaluated in a scan. The difference in time between an XIC and XIOs evaluation in the same rung would be microseconds.

2005年1月15日 · By contrast PLC logic works in the abstract and does not have this physical limitation. This means that either the "0" OR the "1" condition can be considered to convey logical truth. This just falls out of fundamental Boolean logic. In a nutshell I used to teach my PLC classes that ladder rungs were all about the flow of logical truth.

2025年3月27日 · I am working on troubleshooting an issue with our PLC where a single output (O1) has both an XIC and an XIO which controls the activation of a separate output (O2). O2 is supposed to stay latched either through the XIC of O1 or the XIO of O1, depending on the sequence we are in.

2003年5月14日 · 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 therefor the "look for a zero" instruction.

2003年9月7日 · I know this is an elementary question for most. Please reply, even if you feel it is beneath you. I have been in relay logic land for many years, and am still learning how to think PLC logic. So thanks in advance for your help :p XIO or Examine off. Display is …

2003年5月14日 · 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.

2017年3月9日 · He told you wrong. If your goal is to simplify, the logic does the same thing as an XIC(PSC1107A_BLOCKED) OTE (SIDE_A_BLOCKED); XIC(PSC1107B_BLOCKED) OTE (SIDE_B_BLOCKED); It is only copying the bits. They only reason that the existing method would be 'better' would be if there was logic that was changing …