PLCopen Function Blocks

The following function block (FB) library is designed for the purpose of controlling one or more servo axes using the IEC"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 (for more details on FB, refer to Function Blocks).

To offer flexibility, ease of use and reusability, the library consists of command-oriented function blocks that have a reference to the axis, e.g. the abstract data type Axis

The PLCopenA 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 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

MC_MoveAbsolute	performs a single-axis move to a specified endpoint position.
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_MoveAdditive	commands a controlled motion of a specified relative distance. Can also 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_MoveSuperimposed	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_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_Power	controls the power stage: enable(on) and disable (off).
MC_ReadStatus	returns Axis status details with respect to the motion currently in progress.
MC_ReadAxisErr	indicates Drive-related errors.
MC_ResetError	makes the transition from the state ErrorStop to StandStill by resetting all internal axis-related errors and clearing pending commands – it does not affect the output of the FB instances.
MC_ReadParameter & MC_ReadBoolParameter	return the value of a Drive parameter. The returned value has to be converted to Real if required. If not possible, the vendor has to provide a supplier-dependent FB for it.
MC_WriteParameter & MC_WriteBoolParameter	modify the value of a Drive parameter.
MC_ReadActualPosition	returns the value of the actual position.
MC_MachRegist	performs Mark-to-Machine registration
MC_MarkRegist	performs Mark-to-Mark registration
MC_StopRegist	turns off registration
MC_CamTblSelect	selects the Cam tables by setting the pointers to the relevant tables.
MC_CamIn	engages the Cam.
MC_CamOut	disengages the slave from the master axis immediately in a cam block.
MC_GearIn	commands a ratio between the VELOCITY of the slave and master axis.
MC_GearOut	disengages the slave from the master axis.
MC_AddSuperAxis	adds a superimposed axis to a specified axis.
MC_RemSuperAxis	removes a superimposed axis from an axis.