Drive releases

To move a drive, from the PLC some specific release bits must be set on the HLI. The required releases can be set by the PLC via the corresponding control units. More detailed information about the High-Level-Interface (HLI) and the handling with control units can be found in the documentation [HLI].

The release bits of the HLI normally are transferred to the drive amplifier with the cyclic data of the drive. They act directly inside the drive. Additionally, inside the NC kernel also plausibility checks during the drive releases are executed.

For example, an error message is created, if an axis is tried to move by the NC and the necessary release is not set.

The releases are active axis specifically and they are defined in the HLI sector
pAC[Achsindex]^.addr^.McControlLr_Data.

The control units for the drive releases are:

• MCControlBoolUnit_DriveOn: Drive ON (Abbreviation: DriveOn).
• MCControlBoolUnit_TorquePermission: Activation of the drive internal position or velocity controller. The drive creates a torque and turns into control mode (Abbreviation: TorquePermission).
• MCControlBoolUnit_ReleaseFeedhold: Resetting of the drive internal feed hold (Abbreviation: ReleaseFeedhold).

Because not all drive types support the previously described functions, the following table gives an overview about the drive types and their necessary releases. After that in the following chapters the single drive types are described in detail. In the following table an X means, that the assigned function is supported by the drive and that the corresponding release must be set on the HLI: