MechRefPosition

General

Type

Devices supporting the parameter

Lexium LXM52 Drive, Lexium LXM52 Linear Drive,

Lexium LXM62 Drive, Lexium LXM62 Linear Drive,

Lexium ILM62 Drive Module,

Sercos Drive

Traceable

Yes

Functional Description

MechRefPosition represents the reference position that is transferred to the drive via the Sercos bus in units. It is indicated on the drive shaft (gear box output side). The YOffsetPosition from the Y offset generator is taken into account (see Ref-Actual Values). Coordinate displacements with SetPos (FC_SetposDual(), FC_SetposGroup(), FC_SetposSingle()) affect this parameter. The parameter Direction has to be taken into account when interpreting MechRefPosition.

The value of MechRefPosition is calculated once per Sercos cycle (CycleTime). Because the ShaftRefDelay is negative, the following is defined:

RefPosDelay = -ShaftRefDelay

In relation to the reference position for the drive shaft, the MechRefPosition is accelerated by the time RefPosDelay. Therefore, a reference position including YOffsetPosition is shown for the drive shaft after the time RefPosDelay.

NOTE: If ControllerEnable is disabled, the value of MechPosition is cyclically copied to MechRefPosition. Thus, the drive is automatically synchronized to the position for the next release. If ControllerEnable is switched off while the drive is still in motion, then a jump occurs in MechRefPosition. The drive does not react to this jump because it no longer follows the set-point settings when ControllerEnable is switched off.

NOTE: The parameter value is transferred from the master to the slave via the real-time channel of the Sercos. A transmission is only possible in the Sercos phase 4 (operating phase).