MC_GearIn

PLCopen motion icon

 Function Block - Performs a slave axis move which follows the master axis using the ratio specified by RatioNumerator and RatioDenominator.
Once engaged, the slave moves RatioNumerator units for every RatioDenominator units the master moves.

Inputs

Input

Data Type

Range

Unit

Default

Description

Execute

BOOL

FALSE, TRUE

N/A

No default

On the rising edge, request to queue the slave gear ratio move.

Master

AXIS_REF

1 to 256

N/A

No default

Name of a declared instance of the AXIS_REF library function.

Slave

AXIS_REF

1 to 256

N/A

No default

AXIS_REF.AXIS_NUM is the slave axis number.

See AXIS_REF Structure.

RatioNumerator

DINT

-2147483648 to 2147483647

N/A

No default
  • Numerator of slave/master ratio.
  • A positive ratio indicates the slave axis moves in the same direction as the master axis.
  • A negative ratio indicates the slave axis moves in the opposite direction as the master axis.

RatioDenominator

DINT

-2147483648 to 2147483647

N/A

No default
  • Denominator of slave/master ratio.
  • A positive ratio indicates the slave axis moves in the same direction as the master axis.
  • A negative ratio indicates the slave axis moves in the opposite direction as the master axis.

Acceleration

LREAL

No range

User unit/sec2

No default

Trapezoidal: Acceleration rate.

S-curve: Maximum acceleration.

See S-curve and Trapezoidal Acceleration / Deceleration.

Deceleration

LREAL

No range

User unit/sec2

No default

Trapezoidal: Deceleration rate.

S-curve: Unused.

See S-curve and Trapezoidal Acceleration / Deceleration.

Jerk

LREAL

No range

User unit/sec3

No default

Trapezoidal: 0 (zero).

S-curve: Constant jerk.

See S-curve and Trapezoidal Acceleration / Deceleration.

BufferMode

SINT

0 to 1

N/A

No default

Outputs

Output

Data Type

Range

Unit

Description

InGear

BOOL

FALSE, TRUE

N/A

Indicated the slave axis is locked on to the master axis.

Busy

BOOL

FALSE, TRUE

N/A

High from the moment the Execute input goes high until the time the move is ended.

Active

BOOL

FALSE, TRUE

N/A

Indicates this move is the Active move.

CommandAborted

BOOL

FALSE, TRUE

N/A

If TRUE, the command was aborted by another function block.

Error

BOOL

FALSE, TRUE

N/A

Indicates either:

  • An invalid input was specified.
  • The move was terminated due to an error.

ErrorID

INT

No range

N/A

Indicates the error if Error output is TRUE.

See PLCopen Function Block ErrorIDs.

Remarks

SlaveCommandPosition = MasterActualPosition * RatioNumerator / RatioDenominator

  • This function block starts a motion-related action and stores data for calculations and error checking.
    If using a dual-core controller, see Program a Multi-Core Controller.
  • See Function Blocks - General Rules about how inputs and outputs work.
  • When this command is executed, the slave axis accelerates or decelerates (using the Acceleration, Deceleration, and Jerk) to the target velocity determined by the master axis velocity and the ratio.
  • When the slave axis reaches a velocity within the In Gear bandwidth around the target velocity, it locks on to the master, and the InGear output goes high.
  • When the slave is locked to the master, the slave motion is no longer affected by the acceleration, deceleration, and jerk inputs.
    • Example: If the In Gear bandwidth is set to 0.1 User unit/sec, the InGear output turns on if the slave velocity is within +/- 0.1 User unit/sec of the target velocity.
    • The slave axis continues to follow the master axis until this move is aborted.
  • See Main about how this function is used in the Hole punch project.

Aborting Gearing

Gearing functions can generate large accelerations while following the master.

  • If the aborting function block has small, non-zero Jerk, or small acceleration values, it can take a long time for an accelerating axis to reach the target velocity, or position of the aborting function block.
    • If the Jerk and/or acceleration of the aborting function cannot be increased to suitable values, it may be desirable to either:
      • Abort the gearing function with an MC_GearOut with higher accelerations and/or Jerk values (or zero jerk value).
      • Execute the next MC motion function block (e.g., MC_Halt).

Time to Reach the Target Velocity

While following the master, gearing functions can generate large accelerations.

  • If the gearing function is aborted while the axis is currently accelerating, and the aborting function block has small non-zero Jerk or small acceleration values, it can take a long time to reach the target velocity, or position of the aborting function block.
    • If the Jerk and/or acceleration of the aborting function cannot be increased to suitable values, it may be desirable to either:
      • Abort the gearing function with an MC_GearOut with higher accelerations and/or Jerk values (or zero jerk value).
      • Execute the next MC motion function block (e.g., MC_Halt).

Figure 1: MC_GearIn

Time Diagram

Figure 2: Time Diagram

FBD Language Example

Not available.

FFLD Language Example

IL Language Example

Not available.

ST Language Example

(* MC_GearIn ST example *)
   Inst_MC_GearIn( GearInReq, Axis1, Axis2, 2, 1, 150.0, 150.0, 0, 0 );
//Inst_MC_GearIn is an instance of MC_GearIn