Emerson FM-3 manual Master Feedback Group, Torque Group

FM-3 Programming Module Reference Manual

Control Loop Limit

This parameter shows the lowest measured time difference (in microseconds) between the Trajectory Update Rate and the time taken to process the control loop since the last reset. Certain features in the FM-3 require more time to process (i.e. PLS, Capture, Compound Indexes), and therefore will cause lower limits. The software records the lowest measured value and displays it as the limit. To reset the limit to the average and continue tracking the lowest value, the user can click on the Limit button. If the Limit reaches 0, a fault will be generated. If a Limit of less then 75 - 100 usec is seen, it is recommended to switch the update rate to the next higher value.

Margin Average

This parameter shows a running average of the difference (in microseconds) between the Trajectory Update Rate and the time taken to process the control loop since the Status Online tab was brought up. The higher the value, the more time available to run user programs. For Averages less than 150 usec, it is recommended to switch the update rate to the next higher value.

Master Feedback Group

Master Position

Used for synchronized motion, this displays the position of the master encoder in units defined on the Master Units Setup View.

Encoder Position

This displays the position of the master encoder in counts.

Master Velocity

This displays the velocity of the master encoder in master units/second.

Torque Group

Torque Command

This displays the torque command value before it is limited. The torque command may be limited by either the Torque Limit (if the Torque Limit Enable destination is active) or current foldback. Units for this parameter are defined in the Torque Group on the User Units View.

Limited Torque

This is the actual torque commanded to the motor. This value is the result after the TorqueCommand is limited by the current foldback or the TorqueLimit value (if enabled).

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