Emerson unidrive sp User Manual page 232

Safety Mechanical
Product
Information information Installation
Non-rigid position control
In non-rigid position control the position loop is only active when the 'At
Speed' condition is met (see Pr 3.06). This allows slippage to occur while
the speed error is high.
Speed
Reference
Velocity feed forward
The position controller can generate a velocity feed forwards value from
the speed of the reference encoder. The feed-forwards value is passed
to menu, and so ramps may be included if required. Because the
position controller only has a proportional gain, it is necessary to use
velocity feed-forwards to prevent a constant position error that would be
proportional to the speed of the reference position.
If for any reason the user wishes to provide the velocity feed forward
from a source other than the reference position, the feed forward system
can be made inactive, i.e. Pr 13.10 = 2 or 4. The external feed forward
can be provided via Menu 1 from any of the frequency/speed references.
However, if the feed forward level is not correct a constant position error
will exist.
Relative jogging
If relative jogging is enabled the feedback position can be made to move
relative the reference position at the speed defined by Pr 13.17.
Orientation
If Pr 13.10 is 5 the drive orientates the motor following a stop command.
If hold zero speed is enabled (Pr 6.08 = 1) the drive remains in position
control when orientation is complete and hold the orientation position. If
hold zero speed is not enabled the drive is disabled when orientation is
complete.
If Pr 13.10 is 6 the drive orientates the motor following a stop command
and whenever the drive is enabled provided that hold zero speed is
enabled (Pr 6.08 = 1). This ensures that the spindle is always in the
same position following the drive being enabled.
When orientating from a stop command the drive goes through the
following sequence:
1. The motor is decelerated or accelerated to the speed limit
programmed in Pr 13.12, using ramps if these are enabled, in the
direction the motor was previously running.
2. When the ramp output reaches the speed set in Pr 13.12, ramps are
disabled and the motor continues to rotate until the position is found
to be close to the target position (i.e. within 1/32 of a revolution). At
this point the speed demand is set to 0 and the position loop is
closed.
3. When the position is within the window defined by Pr 13.14, the
orientation complete indication is given in Pr 13.15.
The stop mode selected by Pr 6.01 has no effect if orientation is
enabled.
232
Electrical Getting Basic Running the
Installation Started parameters
Actual
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SMARTCARD
Optimization
motor operation
11.21.10 Fast Disable
Software V01.10.00 and later
6.29 Hardware enable
RO Bit
OFF (0) or On (1)
This bit is a duplicate of Pr 8.09 and reflects the state of the enable input.
With software V01.10.00 and later, if the destination of one of the drive
digital I/O (Pr 8.21 to Pr 8.26) is set to Pr 6.29 and the I/O is set as an
input, the state of the input does not affect the value of this parameter as
it is protected, however, it does provide a fast disable function.
The SAFE TORQUE OFF (SECURE DISABLE) input to the drive (T31)
disables the drive in hardware by removing the gate drive signals from
the inverter IGBT's and also disables the drive via the software system.
When the drive is disabled by de-activating the SAFE TORQUE OFF
(SECURE DISABLE) input (T31) there can be a delay of up to 20ms
(typically 8ms) before the drive is disabled. However, if a digital I/O is set
up to provide the fast disable function it is possible to disable the drive
within 600μs of de-activating the input. To do this an enable signal
should be given to both the SAFE TORQUE OFF (SECURE DISABLE)
input (T31) and to the digital I/O selected for the fast disable function.
The state of the digital I/O including the effect of its associated invert
parameter is ANDed with the SAFE TORQUE OFF (SECURE DISABLE)
(T31) to enable the drive
If the safety function of the SAFE TORQUE OFF (SECURE
DISABLE) input is required then there must not be a direct
connection between the SAFE TORQUE OFF (SECURE
DISABLE) input (T31) and any other digital I/O on the drive.
WARNING
If the safety function of the SAFE TORQUE OFF (SECURE
DISABLE) input and the fast disable function is required then
the drive should be given two separate independent enable
signals. A safety related enable from a safe source
connected to the SAFE TORQUE OFF (SECURE DISABLE)
input on the drive. A second enable connected to the digital
I/O on the drive selected for the fast disable function. The
circuit must be arranged so that a fault which causes the fast
input to be forced high cannot cause the SAFE TORQUE
OFF (SECURE DISABLE) input to be forced high, including
the case where a component such as a blocking diode has
failed.
Technical
Onboard Advanced
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NC PT
Unidrive SP Free Standing User Guide
Issue Number: 1
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