Drive enables

To move a drive, the PLC must set enable bits on the HLI. The PLC can set the required enables by activating the associated control units. For more information on the HLI (High Level Interface) and how to handle control units, please refer to the [HLI] documentation.

The HLI enable bits are normally transferred to the drive amplifier together with the cyclic drive data and act directly in the drive. In addition, plausibility checks are carried out in the NC kernel using the drive enables.

For example, if the required enables are not set, an error message is output if an attempt is made to move an axis with the NC.

Enables act on individual axes. For more information, please refer to the HLI documentation in the section Status information of an axis drive.

The control units for drive enables are:

• MCControlBoolUnit_DriveOn: Drive on (abbr.: DriveOn).
• MCControlBoolUnit_TorquePermission: Activate the drive-internal position or speed controller. The drive generates a torque and goes to control (abbr.: TorquePermission).
• MCControlBoolUnit_ReleaseFeedhold: Reset drive-internal feedhold (abbr. ReleaseFeedhold).

Since not all drive types in the above list support the functions described, the table below provides an overview of the enables required for each of the drive types. Each of the drive types is then described in detail in the following sections.
An X in the table indicates that the drive supports the function and the related enable must then be set on the HLI.