Independent Motion Flashcards
Acceleration
AC
1. The AC command is used to designate Acceleration.
2. The Acceleration feedforward command (FA) will help minimize the error for aggresive accelerations.
3. Specify realistic acceleration rates based on physical system parameters such as:
* Motor Torque Rating
* Load
* Amplifier Current Rating
Begin
BG
- The BG command starts a motion on the specified axis or sequence.
- The BG command cannot be executed for any axis in which motion has not completed.
* Use the AM trippoint to wait for motion to complete between moves from embedded code.
Deceleration
DC
1. The deceleration command set the linear deceleration of the motors for independent moves such as PR, PA, and JG moves. The parameters will be rounded down to the nearest factor of 1024 and have units of counts per second squared.
2. DC may be changed during a move in jog mode, but not in a PA or PR move
3. Specify realistic deceleraion rates based on physical system parameters such as:
* Motor Torque Rating
* Loads
* Amplifier Current Rating
Find Edge
FE
1. The FE command moves a motor until a transition is seen on the home input for that axis.
2. The direction of motion depends on the initial state of the homing input ( use the CN command to configure the polarity of the home input).
3. Once the transition is detected, the motor decelerates to a stop.
* This command is useful for creating custom homing sequences
4. Find Edge only searches for a change in state on the Home input. Use FI (Find Index) to search for the encoder index, and use HM (Home) to search for both the Home input and the Index.
* Remember to specify BG after each of these commands.
Find Index
FI
1. The FI and BG commands move the motor until an encoder index pulse is detected.
2. The controller looks for a transition from low to high.
3. There are two stages to the FI command. The first stage jogs the motor at the speed and direction of the JG command until a transition is detected on the index line. When the transition is detected, the position is latched and the motor will decelerate to a stop. In the second stage, the motor will reverse direction and move to the latched position of the index pulse at the speed set by the HV command.
4. At the conclusion of FI, the position is defined as zero.
5. Find Index only searches for a change in the state on the Index.
* Use FE to search for the Home
* Use HM to seatrch for both the Home Input and the Index
* Remember to specify BG after each of these commands.
Home
HM
1. The HM command performs a three stage homing sequence for servo systems and a two stage sequence for stepper motors.
2. The HM command is derived of FE and FI commands.
* During the first stage of the homing sequence, the motor moves at the user-programmed speed until detecting a transition on the homing input for that axis. The speed for step one is set with the SP command. Once the homing input changes state, the motor decelerates to a stop.
* At the second stage, the motor changes directions and approaches the transition again at the speed set with the HV command. When the transition is detected, the motor is stopped instantaneously.
* At the third stage (SERVO only), the motor moves in the positive direction at the speed set with the HV command until it detects an index pulse via latch from the encoder. It returns to the latched position and defines it as position 0.
Homing Velocity
HV
Sets the slew speed for the FI final move to the index and all but the first stage of HM
Increment Position
IP
1. The IP command allows for a change in the command position while the motor is moving. This command does not require a BG
2. -IPm contains the current position of the motor
3. The IP command has four effects depending on the mode of motion being executed
* Motor standing still- Motor will move to specified position with the predefined AC, DC, SP values.
* Motor is moving toward position n - Motor will move a relative move of n0+n1
* Motor is in Jog Mode - The motor will instantly try to servo to a position which is the current instantaneous position plus the specified IP position. SP and AC parameters have no effect. This command is useful when synchronizing 2 axes in which one of the axis;s speed is indeterminante due to a variable diameter pulley
* Motor is a slave in gearing mode- The motor will move with the predefined AC, DC, SP values superimposed on top of the existing gearing motion.
Independent Time Constant Profile Smoothing
IT
1. The IT command filters the acceleration and deceleration functions of independent moves such as JG, PR, PA to produce a smooth velocity profile.
2. The resulting profile, known as smoothing, has continuous acceleration and results in reduced mechanical vibrations.
3. IT sets the bandwidth of the filter where 1 means no filtering and 0.004 means maximum filtering.
4. The IT command also filters the individual axes during Vectore Mode (VM) and Linear Interpolation Mode (LM)
5. The IT filtering results in longer motion time.
6. The use of IT will not effect the trippoints AR and AD
Jog
JG
1. The JG command sets the jog mode and the jog slew speed of the axes
2. When jogging , the motion controller profiles a continuous move at the commanded speed.
3. To stop the motion, use the ST command
4. JG 2 is the minimum non-zero speed
5. -JGm contains the absolute value of the jog speed for the specified axis.
6. The JG command will set the SP register with the absolute value of the ānā value.
Position Absolute
PA
1. The PA command sets the end target of the Position Absolute Mode of Motion
2. The position is reference to the absolute zero position, defined as position 0
3. By default a new PA command may not be issued before the previous PA command has finished executing. This operation may be changed by running in Position Tracking Mode
4. -PAm contains the last commanded position at which motion stopped.
Position Relative
PR
1. The PR command set the incremental distance of the next move.
2. The move is referenced with respect to the current position
3. -PRm contains the current incremental distance for the specified axis
Position Tracking
PT
1. The PT command will place the controller in the position tracking mode. In this mode the controller will allow the user to issue absolute position commands that begin motion immediatly without requiring a BG command.
2. The absolue position may be specified such that the axis will begin motion, continue in the same direction, reverse directions, or decelerate to a stop
3. The PA command is used to give the controller an absolute position target. Motion commands other than PA are not supported in this mode.
4. the motion profile is trapezoidal with the parameters controlled by acceleration, deceleration, and speed (AD,DC,SP)
5. When in the PT mode the ST command will exit the mode.
6. The AM and MC trip points are not valid in this mode.
* MF and MR are recommended with this mode as they allow the user to specify both the absolute position, and the direction.
* The AP trip point may also be used
7. Position tracking is not valid on virtual axes
Limit Switch Deceleration
SD
1. The Limit Switch Deceleration command (SD) sets the linear deceleration rate of the motors when a limit switch has been reached.
2. The SD command may be changed during the move in JG move but not in PR or PA move
Speed
SP
1. The SP command sets the slew speed of any or all axes for independent moves
2. Negative values will be interpreted as the absolute value.
