C5-E CANopen/USB Technical Manual

User-defined units

The controller supports the possibility to set user-defined units. It is thereby possible to set and read out the corresponding parameters, e.g., directly in degrees [°], [mm], etc.

Calculation formulas for user units

Position information

All position values in open loop and closed lop mode are specified in the resolution of the virtual position encoder. This is calculated from the virtual encoder increments (608Fh:1h (Encoder Increments)) per motor revolutions (608Fh:2h (Motor Revolutions)):

If value 608Fh:1h or value 608Fh:2h is set to "0", the controller uses "1" in subsequent calculations. The factory settings are:

  • Encoder increments 608Fh:1 = "2000"
  • Motor revolutions 608Fh:2 = "1"

Example

  608Fh:2h is set to the value "1", 608Fh:1h is set to the value "2000" (default). Thus, the user unit is 2000 increments per revolution. For a stepper motor with step angle of 1.8°, this corresponds to the one tenth step mode.
  With a target position (607Ah) of 2000, the motor moves exactly one mechanical revolution

The physical resolution of the connected position encoder (of the present feedback in general) is set in object 2052h or determined by Auto setup.

Gear ratio

The gear ratio is calculated from motor revolutions (6091h:1 (Motor Revolutions)) per axis rotation (6091h:2 (Shaft Revolutions)) as follows:

If object 6091h:1 or object 6091h:2 is set to "0", the firmware sets the value to "1".

Feed constant

The feed constant is calculated from the feed (6092h:1 (Feed Constant) per revolution of the drive axis (6092h:2 (Shaft Revolutions) as follows:

This is helpful for specifying the lead screw pitch for a linear axis.

If object 6092h:1 or object 6092h:2 is set to "0", the firmware sets the value to "1".

Position

The current position in user units (6064h) and the target position (607Ah) are calculated as follows:

Speed

The speed presets of the following objects can also be specified in user units:


Object Mode Meaning
606Bh Profile Velocity Mode Output value of the ramp generator
60FFh Profile Velocity Mode Speed preset
6099h Homing Mode Speed for searching for the index / switch
6081h Profile Position Mode Target speed
6082h Profile Position Mode Final speed
2032h Profile Torque Maximum speed

The internal unit is revolutions per second (rps).

The factor n for the speed is calculated from the factor for the numerator (2061h) divided by the factor for the denominator (2062h).

When entering values, the following applies correspondingly: Internal value = nspeed x input value

When outputting values, the following applies correspondingly: Output value = internal value / nspeed

Example

  2061h is set to the value "1", 2062h is set to the value "60" (default). Thus, the user unit is "revolutions per minute" and nspeed = 1/60.
  If 60FFh is written with the value "300", the internal value is set to 300 rpm x 1/60 = 5 rps.
  If the motor turns at an internal speed of 5 rps, object 606Bh is set to a speed of 5 / 1/60 = 300 rpm.

Acceleration

The acceleration can also be specified in user units:


Object Mode Meaning
609Ah Homing Mode Acceleration
6083h Profile Position Mode Acceleration
6084h Profile Position Mode Braking deceleration
60C5h Profile Velocity Mode Acceleration
60C6h Profile Position Mode Braking deceleration
6085h "Quick stop active" state (CiA 402 Power State Machine) Braking deceleration

The internal unit is revolutions per second2 (rps2).

The factor n for the acceleration is calculated from the scaling factor for the numerator (2063h) divided by the scaling factor for the denominator (2064h).

When entering values, the following applies correspondingly: Internal value = nacceleration x input value

Example

  2063h is set to the value "1", 2064h is set to the value "60". Thus, the user unit is revolutions per minute per second and nacceleration = 1/60.
  If 60C5h is set to the value "600", the internal value is set to 600 rp(s*min) x 1/60 = 10 rps2.

If object 2063h or object 2064h is set to "0", the firmware sets the value to "1".

Jerk

For the jerk, objects 60A4h:1h to 60A4h:4h can be specified in user units. These objects only affect Profile Position Mode and Profile Velocity Mode.

The internal unit is revolutions per second3 (rps3).

The factor n for the acceleration is calculated from the factor for numerator (2065h) divided by the factor for the denominator (2066h).

When entering values, the following applies correspondingly: Internal value = njerk x input value

Example

  2063h is set to the value "1", 2064h is set to the value "60". Thus, the user unit is "revolutions per minute per second squared" and njerk = 1/60.
  If 60A4h is set to the value "500", the internal value is set to 500 rp(min * s2) x 1/60 = 8.3 rps3.

If object 2065h or object 2066h is set to "0", the firmware sets the value to "1".

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