Yaskawa MotionWorks IEC - Manual (Page 271)

PLCopenPlus Function Blocks for Motion Control 2013-04-13 263
number in the configuration. Tip: Make sure AXIS_REF is
properly declared as a VAR or VAR_GLOBAL in all relevant
POUs.
4648 The parameter number does not exist for the specified axis
4676 The time value must be within 0 to 10 MECHATROLINK cycles.
57617 Instance object is NULL.
57620 The structure size does not match.
Example
Using Y_ReadStringParameter to read the servopack model