Emerson FM-3 Manuel D’Utilisation
143
Parameter Descriptions
This section lists all programmable and feedback parameters available. The parameters are listed
alphabetically by variable name (shown in italics below the on screen name) and give a
description. Range is dynamic and depends on User Unit scaling. The units of the parameters are
dynamic and depend on selected User Units.
alphabetically by variable name (shown in italics below the on screen name) and give a
description. Range is dynamic and depends on User Unit scaling. The units of the parameters are
dynamic and depend on selected User Units.
Absolute Position Valid
AbsolutePositionValid
AbsolutePositionValid
This source is activated when either the DefineHome destination is activated, or any home is
successfully completed (sensor or marker found). This source is deactivated if the drive is
rebooted, an encoder fault occurs, the drive is powered down, or a home is re-initiated.
successfully completed (sensor or marker found). This source is deactivated if the drive is
rebooted, an encoder fault occurs, the drive is powered down, or a home is re-initiated.
Accelerating
Accelerating
Accelerating
This source is active when the FM-3 module is executing an acceleration ramp. A normal
index consists of 3 segments: Accelerating, At Velocity, and Decelerating. The Accelerating
source will be set (active) during this acceleration segment regardless of whether the motor
is speeding up or slowing down. Therefore, this source can sometimes be active when the
motor is decelerating. This could be true when compounding indexes together.
index consists of 3 segments: Accelerating, At Velocity, and Decelerating. The Accelerating
source will be set (active) during this acceleration segment regardless of whether the motor
is speeding up or slowing down. Therefore, this source can sometimes be active when the
motor is decelerating. This could be true when compounding indexes together.
Acceleration Type
AccelType
AccelType
This parameter is used to select the accel/decel type for all motion (homes, jogs and indexes).
The “S-Curve” ramps offer the smoothest motion, but lead to higher peak accel/decel rates.
“Linear” ramps have the lowest peak accel/decel rates but they are the least smooth ramp
type. “5/8 S-Curve” ramps and “1/4 S-Curve” ramps use smoothing at the beginning and end
of the ramp but have constant (linear) accel rates in the middle of their profiles. The “5/8 S-
Curve” is less smooth than the “S-Curve” but smoother than the “1/4 S-Curve”. S-Curve
accelerations are very useful on machines where product slip is a problem. They are also
useful when smooth machine operation is critical. Linear ramps are useful in applications
where low peak torque is critical. Below is a comparison of the 4 ramp types:
The “S-Curve” ramps offer the smoothest motion, but lead to higher peak accel/decel rates.
“Linear” ramps have the lowest peak accel/decel rates but they are the least smooth ramp
type. “5/8 S-Curve” ramps and “1/4 S-Curve” ramps use smoothing at the beginning and end
of the ramp but have constant (linear) accel rates in the middle of their profiles. The “5/8 S-
Curve” is less smooth than the “S-Curve” but smoother than the “1/4 S-Curve”. S-Curve
accelerations are very useful on machines where product slip is a problem. They are also
useful when smooth machine operation is critical. Linear ramps are useful in applications
where low peak torque is critical. Below is a comparison of the 4 ramp types:
•
S-Curve: Peak Accel = 2 x Average Accel
•
5/8 S-Curve: Peak Accel = 1.4545 x Average Accel
•
1/4 S-Curve: Peak Accel = 1.142857 x Average Accel
•
Linear: Peak Accel = Average Accel
FM-3 Programming Module Reference Manual