Examine if open (xio) – Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal User Manual
Page 227

Chapter 16
Bit Instructions
16–3
Examine if Open
XIO
Input Instruction
Bit Address State
0
1
XIO Instruction
True
False
]/[
F1
F2
F3
F4
F5
ZOOM on XIO –]/[– 2.3.0.0.1
NAME: EXAMINE IF OPEN
BIT ADDR: I1:1.0/0 ***************0
EDT_DAT
HHT Ladder Display:
HHT Zoom Display:
Ladder Diagrams and APS Displays:
]/[
I:1.0
0
Logic States:
(online monitor mode)
Specific operation of an XIO instruction having an input data file
address: When an external input device does not complete its circuit, an Off
state is indicated at the input terminal wired to the device. This status of the
terminal is reflected in the input data file at a particular addressed bit. With
the terminal off, the processor finds this bit in the reset condition (0) during
an I/O scan, causing the XIO instruction to be true. When the input device
completes its circuit, the input terminal will be On; the processor then finds
the bit set (1) during an I/O scan, causing the XIO instruction to be false.
Examine if Open (XIO)