Specifications
YASKAWA Inverter Drive A1000 – Crane Software Application Manual 
45 
7.3 Impact Stop Function 
On conveyor belt applications, if the load at some point receives an impact, this can trigger a digital input signal to the 
drive. If a Stop Command is also given, the drive will monitor the torque reference and if it exceeds a preset value, the 
drive will stop. In this section the parameters that control the impact stop function are detailed, the function operation is 
described, and a detailed time chart is shown for an impact stop situation. For this function to be activated, a 
multi-function digital input must be programmed to setting 35 (Impact Stop Command). Do not use on applications where 
an impact does not generate a higher torque reference. 
7.3.1 Impact Stop Parameters (S3-)
S3-01 Impact Stop Creep Frequency (FCR): When an impact stop command is entered and the run command is 
removed, the drive will decelerate to the frequency value stored in this parameter. FCR must be set higher than the Slip 
Prevention Frequency (HF) parameter S1-14, otherwise an oPE22 fault will be triggered. 
S3-02 Impact Stop Creep Time (TCR)
: Time during which the drive will operate at the Impact Stop Frequency FCR 
waiting for an impact to be detected. When this time expires, the drive executes the stopping sequence. 
No.  Parameter Name  Setting Range  Default 
S3-01 
Impact Stop Creep Frequency  0.0 to 20.0 Hz  Determined by A1-02 
S3-02 
Impact Stop Creep Time  0.0 to 20.0 s  10.0 s 
S3-03 Impact Stop Detection Torque FWD (IFOT)
: Sets the torque threshold in the FWD direction at which the drive will 
detect an impact and stop. The parameter is set as a percentage of motor rated torque (vector control) or current (V/f 
control). If set too low, the drive will stop the motor before impact occurs, and if set too high the drive will not detect an 
impact and will continue to operate until TCR expires. 
S3-04 Impact Stop Detection Torque REV (IROT)
: Sets the torque threshold in the REV direction at which the drive will 
detect an impact and stop. The parameter is set as a percentage of motor rated torque (vector control) or current (V/f 
control). If set too low, the drive will stop the motor before impact occurs, and if set too high the drive will not detect an 
impact and will continue to operate until TCR expires. 
S3-05 Impact Stop Detection Time (TIOT)
: Time during which the torque or current reference must surpass the value set 
in IFOT (IROT) before an impact is detected and the drive is stopped. If set too low, drive will stop before an impact 
occurs 
No.  Parameter Name  Setting Range  Default 
S3-03 
Impact Stop Detection Torque FWD  0 to 200 %  100% 
S3-04 
Impact Stop Detection Torque REV  0 to 200 %  100% 
S3-05 
Impact Stop Detection Time  0.0 to 2.0 s  0.3 s 
7.3.2 Impact Stop Operation 
(1) When an Impact Stop Command is received from a digital input and a Stop Command is entered, the drive will 
decelerate to the Impact Stop Creep Frequency FCR if the output frequency is above this value. 
(2)  Once the drive’s output frequency equals the Impact Stop Creep Frequency FCR, the drive will monitor its Internal 
Torque Reference ITR. If the ITR surpasses the value set to the Impact Stop Detection Torque IFOT (IROT) for a 
time longer than the Impact Stop Detection Time TIOT then the drive will have detected an impact and decelerates 
to the Slip Prevention Frequency HF and the regular Stopping Sequence is initiated. 
(3)  If the drive’s Internal Torque Reference ITR fails to surpass the Impact Stop Detection Torque IFOT (IROT) value 
before the Impact Stop Creep Time TCR expires, the drive initiates a regular Stopping Sequence until the brake is 
clamped shut. 










