Block diagram of function module OSS21C

Voltages

Vsys

DC 5 V electronics supply

Voltage supply for electronics and backplane bus communication

VIN

DC 24 V power supply

Voltage supply for the I/O level

Range: DC 20.4 – 28.8 V

VD

DC 10 V driver supply

The voltage supply consists of M via a DC-DC converter

VM

Motor voltage supply

Range: DC 20.4 – 57.6 V

VENC

Encoder voltage supply

Voltage: DC 5 V, typically 100 mA (maximum 200 mA)

Behavior in the event of a DC 24 V power supply failure:

  • The 5 V encoder voltage supply ENC 5 V fails.
  • The encoder counter value stops due to the loss of signal.
  • The digital output DO is deactivated
  • Digital inputs DI1 and DI2 deliver a constant "1" signal in the process data.
  • Digital input DI3 delivers a constant "0" signal in the process data.
  • By evaluating digital input DI3, you can monitor the DC 24 V power supply externally.
Nominal current

Full-step operation
  • The nominal current IN of the motor is always specified for full-step operation by the motor manufacturer.
  • In full-step operation (2-phase), the two windings are fully energized simultaneously; in full-step operation (1-phase), only one winding is fully energized at a time.
  • The following applies: Imax. A = Imax. B = IN

Microstep mode
  • In microstep mode, the two windings are energized in a sine-cosine pattern. This means that the two windings never have full current at the same time.
  • To achieve full load, the winding current can be increased by a factor of √2 = 1.44.
  • The following applies: Imax. A = Imax. B = √2 * IN

Wiring of the windings
  • Depending on how the windings are wired, such as unipolar, bipolar series or bipolar parallel, there will be different permissible nominal motor currents. You can find more information on this in the data sheet for your motor.
Temperature monitoring

The function module is equipped with internal temperature monitoring of the μ-controller and the output stage. You can define limit temperatures in the object list. If a limit value is exceeded or not reached, the function module triggers a configurable error response.

INFORMATION

At an ambient temperature of 60 °C and high load on the function module and neighboring modules with high power loss, small areas of the housing can reach temperatures higher than 85 °C. This is compliant with DIN EN 61010-2-201:2019-04.

Observe the following derating for the motor current for the corresponding motor supply voltage:

[1]

Vertical installation

[2]

Horizontal installation