Homing

Homing is a sequence of predefined motions that are normally required in order to configure the system’s absolute position after power up.

The homing sequence is carried out by searching for an absolute known sensor along the mechanical travel, and updating the internal position accordingly. Once the absolute position has been registered in the drive, the system uses this point as homing position.

For instance, incremental encoder is a kind of feedback that gives a relative position only and does not provide any information regarding the absolute position of the system.

Easy to implement homing by Elmo’s homing interface

Elmo’s intelligent digital servo drives offers 3 homing Options:

1. Elmo commands –

Elmo’s homing enables the following, once an event occurs:

• Modify the sensor position counter
• Log the event position counter into array
• Flag a digital output
• Stop the axis motion

2. PLCopen- ready to use standard function block, The PLCopen are based upon the IEC

1131-3 standard, the only global standard for industrial control programming:

• HomeAbsSwitch – Absolute Switch homing plus limit switches
• HomeLimitSwitch – Homing against limit switches
• HomeBlock – Homing against hardware parts blocking movement
• HomeRefPulse – Homing using encoder reference pulse “Zero Mark”
• HomeRefPulseSet – Homing using a set of encoder reference pulses “Zero Mark”
• HomeDirect – Static Homing, forcing a position from a user reference
• HomeAbsolute – Static Homing, forcing a position from an absolute encoder

3. DS402– Ready to use 36 different homing methods including the “Touch probe homing”, this method defined by the CANopen protocol for capturing the main position sensor.

Design Features

• Support DS402 homing methods (CANopen standard)
• Choose from a variety of  36 “ready to use” different homing methods
• Support PLCopen Homing function blocks (based on IEC 61131 language)
• Reduce development time – ready to use function blocks