Omron TJ1-MC04 - PROGRAMMING 1 Programming Manual page 258

Examples and tips
Origin search using encoder reference pulse "Zero Mark"
This origin search procedure performs origin search by searching
for the "Zero Mark" signal of the encoder. This signal is also known
as "marker" or "reference pulse". It appears one time per full
encoder revolution. The example for this homing procedure is
shown in the figure.
The possible scenarios for origin search using encoder reference
pulse "Zero Mark", depending on the position of the moving part on
power on, are shown in the figure.
The program example that does this origin search sequence is
given below.
'Origin and left limit switch: IN0
'Right limit switch: IN1
REV_IN=-1
BASE(0)
DATUM_IN=0
SERVO=ON
WDOG=ON
DATUM(6)
WA(1)
WAIT IDLE
Static origin search, forcing a position from a user
reference
This origin search procedure performs a static origin search by
directly forcing an actual position. It does not perform any physical
move.
DATUM(0)
PROGRAMMING MANUAL
fig. 31
moving part
min. limit switch ON OFF OFF ON
fig. 32
encoder 2 pulses
REVERSE FORWARD
encoder
max. limit switch
min limit switch
max limit switch
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