PLCopen Function Blocks

This function block (FB) library is designed for controlling one or more servo axes using the IECClosed "International Electrotechnical Commission" IEC is a not-for-profit, non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies 61131-3 PLCopen standard (see Function Blocks for more information).

To offer flexibility, ease of use, and reusability, the library consists of command-oriented function blocks with a reference to the axis (e.g., the abstract data type AXIS_REF Structure).

The PLCopenClosed A vendor -and product- independent worldwide association active in Industrial Control and aiming at standardizing PLC file formats based on XML Library contains function blocks for:

  • Control: Function blocks to define and initialize motion, control power, and reset errors.
  • I/O: Function blocks to control interaction with Digital I/O and Touch Probe and trigger PLCopen Registration functionality.
  • Info: Function blocks to provide information on motion, position, status, and the ability to read and write other drive parameters.
  • PLCopen Motion: Function blocks to execute different types of motion.
  • Profile: Function blocks for master/slave motion.
  • Reference: Function blocks to reset position.
  • Registration: Function blocks to perform registration.

Function BlockClosed A function block groups an algorithm and a set of private data. It has inputs and outputs.

Description

MC_AddSuperAxis

Adds a superimposed axis to a specified axis.

MC_CamIn

Engages the Cam.

MC_CamOut

Disengages the slave from the master axis immediately in a cam block.

MC_CamTblSelect

Selects the Cam tables by setting the pointers to the relevant tables.

MC_GearIn

Commands a ratio between the velocity of the slave and master axis.

MC_GearOut

Disengages the slave from the master axis.

MC_MachRegist

Performs Mark-to-Machine registration.

MC_MarkRegist

Performs Mark-to-Mark registration.

MC_MoveAbsolute

Performs a single-axis move to a specified endpoint position.

MC_MoveAdditive

Commands a controlled motion of a specified relative distance.

  • Can be used to interrupt a motion currently being performed.
    • In this case, the MotionAdditive FB causes the speed, acceleration, and deceleration of the motion already running to be changed to the parameters specified in the MC_MoveAdditive FB.
  • If the MC_MoveAdditive FB is activated in Continuous Mode, the specified relative distance is added to the actual position (at the time of execution).

MC_MoveRelative

Performs a single-axis move of a specified distance relative to the actual position at the time of the start of execution.

MC_MoveSuperimp

  • Commands a controlled motion of a specified relative distance additional to an existing motion.
  • The existing Motion is not interrupted, but is superimposed by the additional motion.

MC_MoveVelocity

Commands a never-ending controlled motion (jog) at a specified velocity.

MC_Power

Controls the power stage: enable(on) and disable (off).

MC_ReadActPos

Returns the value of the actual position.

MC_ReadAxisErr

Indicates Drive-related errors.

MC_ReadBoolPar

&

MC_ReadParam

Return the value of a Drive parameter.

  • The returned value has to be converted to Real if required.
  • If not possible, the vendor must provide a supplier-dependent FB for it.

MC_ReadStatus

Returns Axis status details with respect to the motion currently in progress.

MC_RemSuperAxis

Removes a superimposed axis from an axis.

MC_ResetError

  • Makes the transition from the state ErrorStop to StandStill by resetting all internal axis-related errors and clearing pending commands.
  • This does not affect the output of the FB instances.

MC_Stop

Commands a controlled motion stop and transfers the axis to the Stopping state.

  • It aborts any ongoing function block execution.
  • When the Done output is set, the state transfers to StandStill.
  • While the axis is in Stopping state, no other FB can perform any motion on the same axis.

MC_StopRegist

Turns off registration.

MC_WriteBoolPar

&

MC_WriteParam

Modify the value of a Drive parameter.

Concept Link IconSee Also