Yaskawa MP900 Series Ladder Programming Manual - Manual (Page 251)

5.8 DDC Instructions
5.8.11 Linear Accelerator/Decelerator 1 (LAU)
5-182
[ b ] LAU Instruction for Real Numbers
The LAU instruction for real numbers calculates the speed output value during acceleration, deceleration, and quick
stops, and the current acceleration or deceleration rates using the formula shown below based on predefined parame-
ters.
In this formula, V is the speed output value, V’ is the previous speed output value, VI is the input value for the speed
reference, and Ts is the scan time set value.
„ Speed Output Value during Acceleration
The speed output value during acceleration is calculated as follows:
„ Speed Output Value during Deceleration
The speed output value during deceleration is calculated as follows:
„ Speed Output Value during a Quick Stop
The speed output value during a quick stop is calculated as follows:
„
Current Acceleration/Deceleration Rate
The DVDT (current acceleration/deceleration rate) is calculated as follows after V (speed output) has been calculated:
DVDT = V - V’
ARY (accelerating) turns ON when V’ ≥ 0 and ADV > 0, or when V’ ≤ 0 and ADV < 0.
BRY (decelerating) turns ON at the following times:
• When V’ < 0 and BDV > 0, or when V’ > 0 and BDV < 0
• When V’ < 0 and QDV > 0, or when V’ > 0 and QDV < 0
LSP (zero speed) turns ON when V equals 0. EQR (equal) turns ON when VI equals V.
ARY (accelerating) turns ON when V
≠ V’ and DVDT and V have the same sign and BRY (decelerating) turns ON when V ≠
V’ and DVDT and V do not have the same sign.
If RN (line running) is opened (OFF), the outputs for V and DVDT are set to 0.
ADV (acceleration rate) =
LV × Ts (0.1 ms)
AT (s) × 10,000
If VI > V' (V' ≥ 0), then V = V' + ADV.
If VI < V' (V' ≤ 0), then V = V' − ADV.
If VI < V' (V' > 0), then V = V' + BDV.
If VI > V' (V' < 0), then V = V' − BDV.
BDV (deceleration rate) =
– LV × Ts (0.1 ms)
BT (s) × 10,000
If QS = OFF (VI < V', V' > 0), then V = V' + QDV.
If QS = OFF (VI > V', V' < 0), then V = V' − QDV.
QDV (Quick Stop Rate) =
– LV × Ts (0.1 ms)
QT (s) × 10,000
INFO