A step-by-step guide to the XIO (Examine If Open) instruction which performs the function opposite to the XIC (Examine if Closed). The XIO instruction if is fundamental for working with Programmable Logic Controllers (PLCs).

Jul 20, 2020 · The symbol for the Examine If Open (XIO) instruction is: ——–] / [——– The XIO instruction looks and operates like a normally closed relay contact. There is a memory bit associated with each XIO instruction that is linked to the status of …

Oct 3, 2019 · The XIO instruction is used in logic for conditions that we need to evaluate as false. Similarly, the XIO instruction can generally look at any bit anywhere in memory. If that bit is a 0, the instruction is true.

The XIO instruction examines the data bit to set or clear the rung condition. Bit to be tested. There are various operand addressing modes possible for the data bit, see Bit Addressing for examples. None specific to this instruction. See Index through arrays for array-indexing faults. If Data Bit is true, rung-condition-out is cleared to false.

May 29, 2017 · Learning Basic ControlLogix Instructions (XIC, XIO, OTE), and basic functions (AND, OR, NOT). How to convert logic directly to English.

Jul 21, 2008 · In ladder logic, the NO contact means it's already happened, the associated bit is on, and the power flow continues. The ---[/]--- (XIO) is a little trickier. In relay logic, power flow passes a NC contact until the contacts change state.

Use the bit (relay-type) instructions to monitor and control the status of bits, such as input bits or timer-control word bits.

Aug 25, 2019 · Use the Examine if open (XIO) instruction in your ladder program to determine if a bit is off. When the XIO instruction is executed, if the bit addressed is on (1), then the instruction is evaluated as FALSE.

XIC and XIO instructions are one of the most used basic instructions in plc ladder programming. It is in the category of bit instruction and bit instructions can be used in input and output tags.

Nov 3, 2019 · The third rung introduces the XIO instruction. The XIO will be true only if the input connected to it is open. In the case of internal bits, this instruction is true if the internal bit is off.