Emerson Mentor MP Advanced User's Manual page 60

Parameter
Menu 4
structure
positive. The speed controller will try and accelerate the machine to the final speed demand level with a torque demand defined by the resultant
torque reference. However, the speed cannot exceed the reference because the required torque would be negative, and so it would be clamped
to zero.
Current
Depending on the sign of the final speed demand and the resultant torque the four areas of operation shown below are possible.
- final speed demand
+ final speed demand
+ resultant torque + resultant torque
- final speed demand
+ final speed demand
- resultant torque
-resultant torque
This mode of operation can be used where torque control is required, but the maximum speed must be limited by the drive.
3: Coiler/uncoiler mode
Positive final speed demand: a positive resultant torque will give torque control with a positive speed limit defined by the final speed demand. A
negative resultant torque will give torque control with a negative speed limit of -5rpm.
Negative final speed demand: a negative resultant torque will give torque control with a negative speed limit defined by the final speed demand. A
positive resultant torque will give torque control with a positive speed limit of +5rpm.
Example of coiler operation:
This is an example of a coiler operating in the positive direction. The final speed demand is set to a positive value just above the coiler reference
speed. If the resultant torque demand is positive the coiler operates with a limited speed, so that if the material breaks the speed does not exceed a
level just above the reference. It is also possible to decelerate the coiler with a negative resultant torque demand. The coiler will decelerate down to -
5rpm until a stop is applied. The operating area is shown in the following diagram:
Area for coiler operation, speed
limited to ref and positve torque
Torque
-5rpm
Area for decelerating the coiler, reverse
speed limited and negative torque
60
Keypad and
Parameter x.00
display
Pr 4.08 +
Pr 4.09 (if enabled)
Speed
Pr 3.01
Final speed
demand
Speed
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Parameter description Advanced parameter
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Serial comms
Performance
protocol
Mentor MP Advanced User Guide
Issue Number: 1