Yaskawa MotionWorks IEC - Manual (Page 184)

PLCopenPlus Function Blocks for Motion Control 2013-04-13 176
MC_TouchProbe
The function block will output the axis position when a trigger event
occurs. This function block is specifically designed to work with the high
speed hardware latches on servopacks and LIO option cards. If using the
MP3200iec and MECHATROLINK III servopacks, it is possible to execute
two MC_Touchprobe function blocks simultaneously to capture the rising
and falling edge of a single sensor, or measure the phase difference
between two sensors. See the chart below for configuring the
TRIGGER_REF structure to capture the position for the desired input.