Motion Axis Time Cam (MATC)

The Motion Axis Time Cam (MATC) instruction provides electronic camming of an axis as a function of time or between any two axes in the Master Driven mode.

When executed, the specified axis is synchronized with time or to the Master axis using a Cam Profile established by the

Logix Designer

Cam Profile Editor, or Motion Calculated Cam Profile (MCCP) instruction.

The instruction also provides an easy means to cancel a running time cam anywhere during the cam execution and replace it with a different profile. The replacement is done immediately or scheduled at a specific position in Master Driven mode.

The MATC instruction can be configured for either Time Driven or

Available Languages

Ladder Diagram

Function Block

This instruction is not available in function block.

Structured Text

MATC(Axis, MotionControl, Direction, CamProfile, DistanceScaling, TimeScaling, ExecutionMode, ExecutionSchedule, LockPosition, CamType, LockDirection, InstructionMode);

Operands

Ladder Diagram

Structured Text

MATC (Axis, MotionControl, Direction, CamProfile, DistanceScaling, TimeScaling, ExecutionMode, ExecutionSchedule, LockPosition, CamType, LockDirection, InstructionMode);

The operands are the same as the operands for the relay ladder MATC instruction. For the array operands, you do not have to include the array index. If you do not include the array index, the instruction starts with the first element in the array ([0]).

For the array operands, you do not have to include the array index. If you do not include the index, the instruction starts with the first element in the array ([0]).

For the operands that require you to select from available options, enter your selection as:

MOTION_INSTRUCTION Structure

Description

The MATC instruction executes a Time Cam Profile set up by using the Motion Calculated Cam Profile (MCCP) instruction or by the Studio 5000 Logix Designer application Cam Profile Editor. No maximum velocity, acceleration, or deceleration limits are used in this instruction. The designated Cam profile derived from the associated cam table determines the speed, acceleration, and deceleration of the Slave axis.

The Direction input parameter defines the direction of the Slave axis motion relative to the Master axis. As applied to the Slave axis, the camming direction can be explicitly set as the Same or Opposite or set relative to the current camming direction as Reverse or Unchanged.

The user can use the Distance and Time Scaling functionality to scale Slave motion based on a standard Cam Profile without creating a cam table and calculating a new Cam profile.

The Cam Profile can be executed Once or in Continuous mode by specifying the desired Execution Mode.

The user can also configure the Cam Profile to execute Immediately or Pending completion of a currently running Cam Profile via the Execution Schedule parameter.

To accurately synchronize the Slave axis position to the Master axis position, the user can specify an Execution Schedule setting and an associated Lock Position for the Master axis while the Instruction Mode is Master Driven. If executing in Time-Driven mode, the Lock Position is ignored.

The Cam Type selection allows the user to cancel a running cam and replace it with another cam immediately or schedule it to perform at a specific position in Master Driven mode.

Instruction Mode allows configuring cam execution to either Master Driven or Time Driven mode.

Camming Direction

Cams can be configured to add or subtract their incremental contribution to the axis command position. Control over this behavior is via the Direction parameter.

Camming in the Same Direction

When Same is selected or entered as the Direction for the MATC instruction, the Slave axis position values computed from the Cam Profile are added to the command position of the Slave axis. This is the most common operation, as the profile position values are used as entered in the original cam table. That is, consecutive-increasing profile values result in axis motion in the positive direction and vice versa.

Camming in the Opposite Direction

When Opposite is selected or entered as the Direction, the Slave axis position values computed from the Cam Profile are subtracted from the command position of the Slave axis. Thus, axis motion is in the opposite direction from that implied by the original cam table. In other words, consecutive increasing profile values results in axis motion in the negative direction and vice versa.

Preserving the Current Camming Direction

When Unchanged is selected or entered as the Direction, other position cam parameters can be changed while preserving the current or previous camming direction (same or opposite). This is useful when the current direction is not known or not important. For first-time execution of a cam with Unchanged selected, the control defaults the direction to Same.

Reversing the Current Camming Direction

When Reverse is selected, the current or previous direction of the position cam is changed from Same to Opposite or from Opposite to Same. For first-time execution of a cam with Reverse selected, the control defaults the direction to Opposite.

Specifying the Cam Profile

To execute a MATC instruction, a calculated Cam Profile data array tag must be specified. Cam Profile array tags can be created by the

Logix Designer

tag editor or the MATC instruction by using the built-in Cam Profile Editor, or by executing an Motion Calculate Cam Profile (MCCP) instruction on an existing Cam array.

The data within the Cam Profile array can be modified at compile time by using the Cam Profile Editor, or at runtime with the Motion Calculate Cam Profile (MCCP) instruction. In the case of runtime changes, create a cam array in order to use the MCCP instruction. Refer to the MCCP instruction specification for more detail on converting Cam arrays.

MATC supports two types of Cam Profile array: CAM_PROFILE and CAM_PROFILE_EXTENDED. CAM_PROFILE is calculated from a CAM array. CAM_PROFILE_EXTENDED is calculated from a CAM_EXTENDED array, which provides better precision.

For CAM_PROFILE array, all but the status and type elements of the CAM_PROFILE array element structure are hidden in the Studio 5000 Logix Designer tag editor. Use the status parameter to indicate that the CAM_PROFILE array element has been calculated. If a camming instruction begins to execute with uncalculated elements in a CAM_PROFILE, an error occurs. The type parameter determines the type of interpolation applied between this cam array element and the next cam element (for example, linear or cubic).

For CAM_PROFILE_EXTENDED array, the status, master and slave values, type, and C0, C1, C2, C3 coefficients are visible in the Studio 5000 Logix Designer tag editor. Use the status parameter to indicate that the CAM_PROFILE array element has been calculated. If a camming instruction begins to execute with uncalculated elements in a CAM_PROFILE, an error occurs. The master and slave define the x and y value of the cam element. The type parameter determines the type of interpolation applied between this cam array element and the next cam element (for example, linear or cubic). The C0, C1, C2, and C3 are coefficients that define the shape between two cam elements.

Cam Profile Array Checks

The Status member of the first element in the Cam Profile array is special and used for data integrity checks. For this reason, the MATC must always specify the cam profile with the starting index set to 0. This first cam profile element Status member can have the following values:

Before starting a cam on a specified axis, the MATC instructions checks if the Cam Profile array has been calculated by checking the value of the first cam profile element’s Status member. If Status is 0 or 1 then the cam profile has not been calculated yet and the MATC instruction errors. If the Cam Profile array has been completely calculated (Status > 1), the instruction then increments the Status member indicating that it is in use by this axis.

When the cam completes, or terminates, the Status member of the first cam profile array element is decremented to maintain track of the number of cams actively by using the associated cam profile.

Linear and Cubic Interpolation

Time cams are fully interpolated. This means that if the current master time value does not correspond exactly with a point in the cam table associated with the cam profile, the Slave axis position is determined by linear or cubic interpolation between the adjacent points. In this way, the smoothest possible slave motion is provided.

Each point in the Cam array that was used to generate the Cam Profile can be configured for linear or cubic interpolation.

Electronic camming remains active through any subsequent execution of jog, or move processes for the slave axis. This allows electronic camming motions to be superimposed with jog, or move profiles to create complex motion and synchronization.

Scaling Time Cams

A time cam profile can be scaled in both time and distance when it is executed. This scaling is useful because it allows the stored cam profile to be used only for the form of the motion with the scaling used to define the time or distance over which the profile is executed.

When MATC instruction specifies a Cam Profile array, the master coordinate values defined by the Cam Profile array take on the time units (seconds) and the slave values take on the units of the Slave axis. By contrast, the Time and Distance Scaling parameters are "unit less" values that are used as multipliers to the Cam profile.

By default, both the Time and Distance Scaling parameters are set to 1. To scale a time Cam profile, enter a Time Scaling or Distance Scaling value other than 1.

Increasing the Time Scaling value of a Cam profile decreases the velocities and accelerations of the profile, while increasing the Distance Scaling value increases the velocities and accelerations of the profile. To maintain the velocities and accelerations of the scaled profile approximately equal to those of the unscaled profile, the Time Scaling and Distance Scaling values should be equal. For example, if the Distance Scaling value of a profile is 2, the Time Scaling value should also be 2 to maintain approximately equal velocities and accelerations during execution of the scaled time cam.

Execution Modes

The New Cam and Replacement Cam can have an Execution Mode of Once or Continuous. Execution Mode can be selected to determine how the cam motion behaves when the time moves beyond the end point of the Cam Profile defined by the original cam table.

Once

When Once is selected (default), the specified cam profile, once started, executes till the Cam boundary is crossed. When the Master axis moves outside the range of the profile, cam motion on the Slave axis stops and the Process Complete (. PC) bit of MATC Instruction is set and the Time Cam Status bit in Slave axis’ Motion Status word is reset.

The diagram illustrates the execution of New Cam in Time Driven Mode with Execution Schedule of Immediate and Execution Mode of Once.

When the Active Cam starts, the .IP and .AC bits are set. The Time Cam Status bit in Slave axis’ Motion Status word is also set. When the time moves beyond the range of the Cam profile, the Active Cam .PC bit gets set and the .IP and .AC bits are reset. The Time Cam Status bit in Slave axis’ Motion Status word is reset.

Continuous

When Continuous Mode is selected, the Cam profile is executed indefinitely. With continuous operation, the slave positions are reset when the time moves beyond the end of the Cam profile causing the Cam profile to repeat indefinitely. This feature is useful in rotary applications where it is necessary that the time cam run continuously in a rotary or reciprocating fashion. To generate smooth continuous motion by using this technique, however, care must be taken in designing the cam points of the cam table so that there are no position, velocity, or acceleration discontinuities between the start and end points of the calculated Cam profile.

The diagram illustrates the execution of New Cam in Time Driven Mode with Execution Schedule of Immediate and Execution Mode of Continuous. At time value of 2, the Active Cam profile crosses the Cam boundary and the second cycle of the Cam profile starts, at time value of 4 the second cycle of Cam profile completes and the third cycle starts, this goes on indefinitely.

Execution Schedule

The Execution Schedule parameter controls the MATC instruction’s execution schedule. An Execution Schedule of Immediate (0) and Pending (1) is used in both Master Driven Mode and Time Driven Mode.

Immediate

By default, the execution schedule of MATC instruction is Immediate. In Immediate execution, the Slave axis is immediately locked to the time master coordinate, according to the specified Cam Profile. there is no delay in enabling of the time camming process.

Active Cam

In the Immediate Active Cam case, there is no delay in execution of the time cam. In this case, the Lock Position parameter is irrelevant.

The diagram illustrates Immediate Active Cam initiated in Time Driven Mode and Execution Mode of Once. When the camming process is initiated, the Slave axis synchronized with the time and follows the Cam Profile. The Time Cam Status bit is set at the beginning, and Time Cam Lock Status of the Slave axis’ Motion status word remains unchanged as it is unused in Time Driven mode. The Active Cam’s .PC bit is set when time moves beyond the range of the Cam Profile. The Time cam Status of the Slave axis’ Motion status word bit is reset then.

Replace and Restart Cam

In the Immediate Replace and Restart cam case, the replacement cam replaces the Active Cam immediately.

The diagram illustrates Immediate Replace and Restart cam execution in Master Driven Mode, Execution Mode of Once and Lock Direction of Immediate Forward Only. The Active cam initiates the camming process, and the Replacement cam is initiated immediately.

The Time Cam Status and Time Cam Lock Status of the Slave axis’ Motion status word is set. The replacement Cam’s .PC bit is set when time moves beyond the range of the Replacement Cam Profile.

Replace and Continue Cam

In the Immediate Replace and Continue Cam case, the Replacement Cam replaces the Active Cam immediately at the point at which the replacement was initiated.

The diagram illustrates Immediate Replace and Continue cam execution with this configuration:

The Active cam initiates the camming process, and the Replacement cam replaces the Active Cam immediately. The Slave axis is synchronized with the Time and follows the Replacement Cam Profile.

The Time Cam Status of the Slave axis’ Motion status word is set. The replacement Cam’s .PC bit is set when time moves beyond the range of the Replacement Cam Profile.

Pending Cam Execution: Alternatively, the MATC instruction’s execution can be deferred pending completion of an executing Time cam. An Execution Schedule selection of Pending is blends two Time Cam profiles without stopping motion.

The Pending execution feature is useful in applications like high-speed packaging when a Slave axis must be locked into a Master axis and accelerated by using a specific profile to the proper velocity. When this acceleration profile is done, it must blend into the operating profile, which is typically executed continuously. To stop the Slave axis, the operating profile is blended into a deceleration profile such that the axis stops at a known location as shown in the diagram.

To confirm smooth motion across the transition, the profiles must be designed such that no position, velocity, or acceleration discontinuities exist between the end of the current profile and the start of the new one. This is done by using the Studio 5000 Logix Designer application Cam Profile Editor.

If an Execution Schedule of Pending is selected without a corresponding Active Cam profile in process, the MATC instruction executes but no camming motion occurs until another MATC instruction with a non-pending Execution Schedule is initiated. This allows pending Cam Profiles to be preloaded prior to executing the initial cam. This method addresses cases where immediate cams would finish before the pending cam could be reliably loaded.

Replacement Cam effect on a Pending Cam :This diagram shows an example of how Pending Cam is affected when a Replacement Cam starts. The status transitions are indicated by the dotted vertical lines in the diagram. When the Replacement Cam executes, the Pending Cam’s .IP bit is set and the Replace and Restart Cam Profile runs.

(1) Active Cam starts in Time Driven Mode with Lock Direction of Immediate Forward only.

(2) Pending Cam is enabled and waiting for the completion of the Active Cam. The Pending Cam’s. IP and .DN bits are set.

(3) Replacement Cam executes in Time Driven mode before the end of the Active Cam profile completes. The Pending Cam’s .IP bit resets and no change in .AC bit.

(4) Cam Complete. The Replacement Cam’s .PC bit is set.

If the Cam Type is Replace and Restart or Replace and Continue with the Execution Schedule of Pending, then the MATC instruction’s .ER flag is set.

Both the Pending Cam and an Active Cam must be in the same instruction mode - either both must be in Time Driven Mode, or both must be in Master Driven Mode. An instruction that pends a Cam to an Active Cam in a different mode causes the Active Cam’s .ER to set.

All pending Cams must use the Immediate Forward or the Immediate Reverse Lock Direction. A pending Cam with a specified Lock Position with a Position Forward Only or Position Reverse Only Lock Direction causes a LOCK_DIRECTION_CONFLICT (95) error. (See MDSC Error Codes for a list of runtime error codes.) A second pending Cam overlays the first pending Cam in memory.

Cam Type

The Cam Type parameter indicates that the programmed cam is a new or replacement cam.

The selection allows the user to choose:

New Cam

New Cam should be used when the user wants the programmed cam to be a completely new cam. This is the default value for the Cam Type parameter and provides backward compatibility for the Studio 5000 Logix Designer application.

New Cam starts its cam profile at the beginning or when the Pending Cam starts after the Active Cam is complete.

The diagram illustrates the execution of a New Cam. The left side shows the execution in Time Driven Mode, where the Slave axis is synchronized with time using cam profile. The right side shows the execution of the same profile in Master Driven Mode where the Slave axis is locked to the Master axis.

Replace and Restart

Use the enumeration Replace and Restart to replace the current running cam. The replacement happens without any consideration of velocity, acceleration, or jerk disturbances.

The user is responsible for minimizing any velocity, acceleration, or jerk disturbances through proper Cam design.

The diagram illustrates the execution of Replace and Restart in Time Driven Mode with Execution Schedule of Immediate and Execution Mode of Once.

When the Active Cam starts, the Slave axis is synchronized with time by using the cam profile. The Active Cam profile is replaced with the Replacement Cam when it is initiated, and then the Slave axis starts moving according to the Replacement Cam profile synchronized in time until the cam completes.

Replace and Continue

Use the enumeration Replace and Continue to replace the Active Cam at any point when it is in progress. At the replacement point, the Replacement Cam starts to interpolate the Slave axis.

The diagram illustrates the execution of a Replace and Continue in Master Driven Mode with Execution Schedule of Immediate and Execution Mode of Continuous.

The green dotted line indicates the positions of Slave axis if the Replacement Cam started at the same time as Active Cam. The blue dotted line indicates the Slave axis positions if the Active Cam continued execution beyond the replacement point. The change in Slave Position at the replacement point is due to the cam profile defined for the Replacement Cam.

Lock Direction

Lock Direction indicates the direction of the Master axis that generates the Slave motion. In Time Driven Mode, time cams are programmed with a Lock Direction of None.

In Master Driven Mode, the time cams are programmed with a following Lock Direction and are used for Cam Type Replace and Restart and Replace and Continue.

Immediate Forward Only: The Replacement Cam replaces the Active Cam immediately when Master axis is moving in the forward direction.

Immediate Reverse Only: The Replacement Cam replaces the Active Cam immediately when Master axis is moving in the reverse direction.

The diagram illustrates Immediate Replace and Restart Cam execution in Master Driven Mode with Execution Mode of Once and Lock Direction is Immediate Reverse Only.

(1) Active Cam Start: The Active Cam with Lock Direction of Immediate Forward only starts when Master axis moves in the forward direction. The Time Cam Status and Time Cam Lock Status of the Slave axis’ motion status word bits are set.

(2) Active Cam Unlocked: Due to Master axis reversal, the Active Cam is unlocked, and the Time Cam Lock Status of the Slave axis’ Motion status word is reset.

(3) Replacement Cam Start: While Master axis is moving in the reverse direction, the Replacement Cam replaces the Active Cam immediately and Replacement Cam’s .AC bit is set indicating that the Replacement Cam is interpolating the Slave axis. The Time Cam Lock Status of the Slave axis’ Motion status word is set.

The Replacement Cam’s .PC is set when Master axis moves beyond the range of the Replacement Cam Profile. The Time Cam Status and Time Cam Lock Status of the Slave axis’s Motion status word bits are reset then.

Position Forward Only: The Replacement Cam replaces the Active Cam when the cam reaches the replacement point, while the Master axis moves in the forward direction.

Position Reverse Only: Same as Position Forward Only except that the Master axis is moving in the reverse direction.

The diagram illustrates Immediate Replace and Continue Cam execution in Master Driven Mode.

(1) Active Cam Start: The Active Cam with Lock Direction of Immediate Forward only starts when Master axis moves in the forward direction. The Time Cam Status and Time Cam Lock Status of the Slave axis’ motion status word bits are set.

(2) Active Cam Unlocked: Due to Master axis reversal, the Active Cam is unlocked, and the Time Cam Lock Status of the Slave axis’ Motion status word is reset.

(3) Replacement Cam Start: While the Master axis is moving in the reverse direction, the Replacement Cam is initiated with Active Cam still unlocked with following configuration:

When Master axis starts moving in reverse direction and reaches the Lock position of 10 units, then the Replacement Cam’s .AC bit is set indicating that the Replacement Cam is interpolating the Slave axis.

The Replacement Cam’s .PC bit is set when Master axis moves beyond the range of the Replacement cam Profile. The Time Cam Lock Status of the Slave axis’s Motion status word bit is reset then.

Stopping a Cam

Like other motion generators (for example, jog, move, gear) Active Cams must be stopped by the various stop instructions, MAS, or MGS. Cam motion must also stop when the ControlLogix processor changes OS modes. The MAS instruction, in particular, must be able to specifically stop the camming process. This behavior should be identical to the MAS functionality that stops a gearing process.

Merging from a Cam

Like other motion generators (for example, jog, move, gear) Active Cams must also be compliant with motion merge functionality. Moves and Jogs, in particular, must be able to merge from active camming. This behavior should be identical to the merge functionality applied to a gearing process.

Structure

See Input and Output Parameters Structure for Single Axis Motion Instructions for the input and output parameters that are available for the MATC instruction via the Master Driven Speed Control (MDSC) function. Before any of these parameters is active, you must execute an MDAC instruction and it must be active (IP bit is set).

Affects Math Status Flags

No

Major/Minor Faults

None specific to this instruction. A major fault can occur if an uninitialized reference or a reference of incorrect type is passed to the Axis Operand. See Index through Arrays for array-indexing faults.

Execution Conditions

In Structured Text, EnableIn is always True during a normal scan. If the instruction is in the control path activated by the logic, it executes.

Ladder Diagram

Error Codes

See Motion Error Codes (.ERR) for Motion Instructions.

Extended Error Codes

Extended Error Codes provide additional instruction-specific information for the Error Codes that are generic to many instructions. Extended error codes for the PARAMETER_OUT_OF_RANGE(13) error code lists a number that refers to the number of the operands, as they are listed in the faceplate, from top to bottom, with the first operand being counted as zero. Therefore, for the MATC instruction, an extended error code of 5 would refer to the Time Scaling operand’s value. You would then have to check your value against the accepted range of values for the instruction.

SEGMENT field

The .SEGMENT field for the ILLEGAL_CAM_TYPE (28), ILLEGAL_CAM_ORDER (29) or INVALID_CAM_PROFILE_ELEMENT (179) error codes indicate the Cam Profile array element that contains, respectively, an invalid Cam Profile type (not linear or cubic), a non-ascending Master position or an invalid value (such as overflow or not a number). Therefore, INVALID_CAM_PROFILE_ELEMENT with .SEGMENT field value of 3 indicates that the fourth element (or [3]) of the Cam Profile array contains the invalid number. Use the Motion Calculate Cam Profile (MCCP) instruction or Cam Profile editor to recalculate the Cam Profile and ensure the master and slave values do not contain an invalid value.

Status Bits

Time Cam Status

This Status bit indicates that the MATC profile is in progress and sets when the MATC command is initiated on the Slave axis.

Resets with either of these conditions:

Time Cam Lock Status

The Time Cam Lock Status bit is valid only in Master Driven mode and when the Execution schedule is Immediate. The Time Cam Lock Status bit indicates that the status when the Master axis starts driving the Slave axis based on the cam profile and Slave Direction and sets when the Master axis satisfies these conditions: Execution Mode, Lock Direction, and Lock Position.

Resets with either of these conditions:

Time Cam Pending Status

This Status bit indicates that the MATC profile is pending the completion of an executing cam profile and sets when these conditions are met:

Resets with either of these conditions:

The diagram illustrates Immediate Replace and Continue Cam execution in Master Driven Mode.

(1) Active Cam Start

The Active Cam with Lock Direction of Immediate Forward only starts when the Master axis moves in the forward direction. The Time Cam Status and Time Cam Lock Status of the Slave axis’ motion status word bit sets. The Time Cam Pending Status bit of the Slave axis’ Motion Status bit is Unchanged.

(2) Active Cam Unlocked

Due to Master axis reversal, the Replacement Cam unlocks, and the Time Cam Lock Status of the Slave axis’ Motion status word resets. The Time Cam Status of the Slave axis’ Motion Status bit is Unchanged.

(3) Replacement Cam Start

While the Master axis is moving in the reverse direction, the Replacement Cam initiates with Active Cam still unlocked with this configuration:

The Time Cam Pending Status of the Slave axis’ Motion status word bit sets. The Time Cam Status and the Time Cam Lock Status of the Slave axis’ Motion Status bits are Unchanged.

(4) Replacement at Lock Position

When the Master axis starts moving in the reverse direction and reaches the Lock position of 10 units, the Time Cam Lock Status of the Slave axis’ Motion status word bit sets, and the Time Cam Pending Status of the Slave axis’ Motion status word bit resets. The Time Cam Status of the Slave axis’ Motion Status bit is Unchanged.

Master Driven Speed Control (MDSC) and Motion Direct Command Support

The Motion Direct commands are not available in the instruction tree for the MATC instruction. You must program an MATC in one of the supported programming languages before you execute an MAM or MAJ in Time Driven Mode. A runtime error occur if an MATC is not previously executed in an MAM and MAJ in Master Driven Mode.

Example

Relay Ladder Logic

Structured Text

MATC(Axis1,matc_motion_ctrl,1,cam_profile[0],2,2,Once,Immediate,0,NewCam,None,TimeDrivenMode);