Yaskawa MotionWorks IEC User Manual
Page 181
PLCopenPlus Function Blocks for Motion Control 2013-04-13
173
NOTE: In an unwinding application (derived from this brake control)
material tension is the target, not motor torque. The instantaneous
diameter of the roll should be taken into account to transform the “User
tension setpoint”. Also additional inertia compensation by modification of
the torque setpoint for acceleration / deceleration is common from
instantaneous weight data (weight is commonly estimated from diameter).
Additionally in unwinding applications, in the case of loose material (same
condition as material break), a negative slow velocity reference is usually
applied in order to “rewind” the loose material. In this case, this has to be
provided by external programming.