Digital Switch Input - Dsw - Omron SYSMAC C200HS Operation Manual

Advanced I/O Instructions
5-28-2 DIGITAL SWITCH INPUT – DSW(––)
Overview
Precautions
304
Ladder Symbols
DSW(––)
IW
OW
R
DSW(––) is used to read the value set on a digital switch connected to I/O Units.
When the execution condition is OFF, DSW(––) is not executed. When the exe-
cution condition is ON, DSW(––) reads the 8-digit value set on the digital switch
from IW and places the result in R.
The 8-digit value it is placed in R and R+1, with the most significant digits placed
in R+1.
DSW(––) reads the 8-digit value in 20 executions, and then starts over and con-
tinues reading the data.
The digital switch must provide four data lines and one latch signal line and read
signal line for each digit being input.
I/O refreshing must be performed for all I/O points used by DSW(––) each time it
is executed to ensure effective operation. The I/O REFRESH instruction must
thus be used with DSW(––) whenever DSW(––) is used in a subroutine to en-
sure that the I/O points are refreshed each execution. Refer to page 315 for an
example of this type of programming.
DSW(––) will be executed from the first cycle whenever program execution is
started, including restarts made after power interruptions.
Do not use DSW(––) more than once in the program.
DSW(––) cannot be used for I/O Units mounted to Slave Racks.
Note Input and output bits not used here can be used as ordinary input and output bits.
Section 5-28
Operand Data Areas
IW: Input word
IR, SR, AR, HR, LR
OW: Output word
IR, SR, AR, HR, LR
R: First result word
IR, SR, AR, DM, HR, LR