Part 2 - Extensions
The PLCopen Motion Control Extensions specification, Part 2 is an addition to the basic document Part 1, and should not be seen as stand alone documents. For instance, Part 2 adds information to the state diagram, but only the added transitions are shown in this document.
containing additional function blocks. Part 2 was released in September 2005 as version 1.0.
Extending the set of Function Blocks for Motion Control
The defined ExtensionsMC_TouchProbe - is used to record an axis position at a trigger event
MC_AbortTrigger - is used to abort an on-going trigger event coupled to an axis as in MC_TouchProbe
MC_ReadDigitalInput - gives access to the datatype INPUT_REF (as used in MC_TouchProbe), and provides the status of the referenced input (BOOL)
MC_DigitalCamSwitch - provides the analogy to switches on a motor shaft: it commands a group of discrete output bits to switch in analogy to a set of mechanical cam controlled switches connected to an axis. Forward and backward rotations are allowed.
MC_ReadDigitalOutput - gives access to the value of an output of OUTPUT_REF , as used in MC_DigitalCamSwitch
MC_WriteDigitalOutput - writes a value to an output of OUTPUT_Ref , as used in MC_DigitalCamSwitch
MC_SetPosition - shifts the coordinate system of an axis by manipulating both the set-point position as well as the actual position of an axis with the same value without any movement caused (Re-calibration with same following error). This FB can be used during motion without changing the commanded position, which is now positioned in the shifted coordinate system.
MC_SetOverride - sets the values of override parameters.
MC_TorqueControl - exerts torque continuously with a specified torque level using a defined ramp, and sets the InTorque output if the torque level is reached. Can be used as continuous motion, and for discrete motion. This function block is applicable for force and torque.
MC_ReadActualVelocity - returns the value of the actual velocity as long as enabled.
MC_ReadActualTorque - returns the value of the actual torque as long as enabled. MC_GearInPos - commands a gear ratio between the position of the slave and master axes from the synchronization point onwards.
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