Rockwell Automation 9VT201-007HTNNN, User Manual, Page: 211 / 224

Application Notes C-15
Publication 9VT-UM001D-EN-P
Ramp to
Stop
This method uses drive output reduction to stop the load.
1. On Stop, drive output will decrease according to the programmed pattern from its
present value to zero. The pattern may be linear or squared. The output will decrease
to zero at the rate determined by the programmed [Maximum Freq] and the
programmed active [Decel Time x]
2. The reduction in output can be limited by other drive factors such as bus or current
regulation.
3. When the output reaches zero the output is shut off.
4. The motor, if rotating, will coast from its present speed for a time that is dependent on
the mechanics of the system (inertia, friction, etc).
Ramp to
Hold
This method combines two of the methods above. It uses drive output reduction to stop the
load and DC injection to hold the load at zero speed once it has stopped.
1. On Stop, drive output will decrease according to the programmed pattern from its
present value to zero. The pattern may be linear or squared. The output will decrease
to zero at the rate determined by the programmed [Maximum Freq] and the
programmed active [Decel Time x]
2. The reduction in output can be limited by other drive factors such as bus or current
regulation.
3. When the output reaches zero 3 phase drive output goes to zero (off) and the drive
outputs DC voltage on the last used phase at the level programmed in [DC Brake
Level] Par 158. This voltage causes a “holding” brake torque.
4. DC voltage to the motor continues until a Start command is reissued or the drive is
disabled.
5. If a Start command is reissued, DC Braking ceases and the drive returns to normal AC
operation. If an Enable command is removed, the drive enters a “not ready” state until
the enable is restored.
Mode Description
DC Hold Time
DC
Hold
Level
S top
Command
Time
Output Voltage
Output Current
M otor S peed
Output Voltage
Output Current
Zero
Command
S peed
DC
Hold Level
Time
Output Voltage
Output Voltage
Output Current
Output Current
M otor S peed
Output Voltage
Output Current
M otor S peed
R e-issuing a
S tart Command
S top
Command
Zero
Command
S peed