Encoder Evaluation

Invert Encoder Counting Direction

If set to TRUE, the Invert Encoder Counting Direction parameter reverses the encoder counting direction.

• FALSE: The polarity of the axis movement agrees with the counting direction of the acquisition hardware.
• TRUE: The polarity of the axis movement is in the opposite sense to that of the counting direction of the acquisition hardware.

Scaling Factor Numerator and Scaling Factor Denominator (default: 1.0)

The scaling factor is divided into a numerator and a denominator. It is used to convert the path increments into axis positions or to calculate a user unit from encoder increments.

Position Bias

The zero offset shift is an offset that absolute encoders use to align their position in the machine coordinate system and is thus used to define the machine-related zero point. The offset value of the zero offset shift is added to the encoder position to determine the axis position.

Modulo Factor (e.g. 360.0°)

The value of the Modulo Factor (e.g. 360.0°) is the value for calculating modulo turns and modulo positions from the absolute axis position. For rotary axes, the modulo factor is the "path distance" that forms one revolution. If the actual value is acquired, for instance, in degrees, 360.0° should be entered here.

Tolerance Window for Modulo Start

The Tolerance Window for Modulo Start should be large enough to allow backward movement when a modulo forward command is executed in the window area. Conversely, the Tolerance Window for Modulo Start should be large enough to allow forward movement when a modulo backward command is executed in the window area.

Encoder Mask (maximum encoder value)

The encoder mask defines the number of allowed increments until the feedback value overflows. In most cases, the increments are not the real encoder increments due to internal encoder overflow calculation on the connected hardware.

Encoder Sub Mask (absolute range maximum value)

The encoder sub mask defines the number of increments per motor revolution.

Noise level of simulation encoder

This parameter creates artificial noise for the simulation axis by setting a level to make it appear more realistic.

Reference System

Use the Reference System parameter to select how the encoder values should be interpreted:

INCREMENTAL

INCREMENTAL mode does not use absolute characteristics of the physical feedback system, but can be used with both incremental and absolute encoder systems. After starting the control, homing is required to initialize the actual position of the axis.

INCREMENTAL (singleturn absolute)

This mode extends the INCREMENTAL mode and can be used instead.

If in this mode the retain data of the NC-SAF task and the axis parameter Data Persistence are activated, the system starts up with the last stored position. If a single-turn absolute encoder is used at the same time, a deviation of up to half an encoder revolution is also taken into account and the axis can be operated within these limits without homing. The absolute range of the encoder system is defined by the parameter Encoder Sub Mask.

ABSOLUTE

The ABSOLUTE mode can be used with multi-turn absolute encoder systems. The prerequisite is that the encoder system or the motor is installed in such a way that there can't be overflow of the position feedback within the travel path. An overflow would be acknowledged with a runtime error.

ABSOLUTE MULTITURN RANGE (with single overflow)

The ABSOLUTE MULTITURN RANGE mode can also be used with multi-turn absolute encoder systems. The encoder system can be installed in any way, so that a maximum of one overflow may occur in the travel path. To ensure correct evaluation, the two end positions must be parameterized.

The total travel path must be less than the absolute range of the encoder. The absolute range of the encoder system is defined by the parameter Encoder Mask.

ABSOLUTE SINGLETURN RANGE (with single overflow)

The ABSOLUTE SINGLETURN RANGE mode can be used with single-turn absolute encoder systems. The encoder system can be installed in such a way that an overflow is located in the travel path. To ensure correct evaluation, the two end positions must be parameterized.

The total travel path must be less than the absolute range of the encoder, i.e. less than one encoder revolution. The absolute range of the encoder system is defined by the parameter Encoder Sub Mask.

ABSOLUTE (modulo)

The ABSOLUTE (modulo) mode can be used when the travel path of an axis exceeds the absolute range of the encoder system. For example, in the case of an endlessly running conveyor belt.

To initialize the position of the axis correctly at system start, the retain data of the NC-SAF task and the parameter Data Persistence of the axis must be activated. Furthermore, the parameter Modulo Factor of the encoder of the NC axis must be parameterized correctly. The axis position is initialized to this module range after the system startup.

When switched off, the axis may be mechanically displaced by a maximum of half of the absolute range. This maximum distance is defined by the Encoder Sub Mask parameter. The Encoder Sub Mask is typically set to the increments of one motor revolution, but can also be set to the entire absolute range here.