Communication and Electronics Gear Settings

In this section, we explore how the Motion4Sim Servo Controller communicates with AASD servo drives and the role of the Electronics Gear Settings, specifically the parameter PN98 in the servo driver. Understanding this parameter is key to optimizing motor performance, speed, and resolution.

Encoder Resolution and PN98 Basics

The AASD servo drives support a resolution of 10,000 positions per revolution, as reported by the built-in encoder. The PN98 parameter in the servo driver defines how many motor steps correspond to each pulse sent by the controller:

• PN98 = 1: Each pulse corresponds to 1 motor step. The servo driver adjusts the encoder to match this single-step movement.

• PN98 = 10 or 20: Each pulse corresponds to 10 or 20 motor steps, respectively. The servo driver advances the encoder by the specified number of steps per pulse.

This setting effectively acts as an electronic gearbox, scaling the relationship between controller pulses and motor movement.

Pulse Frequency and Speed

To achieve the desired motor speed—particularly full speed—it’s critical to calculate the required pulse frequency based on the PN98 setting:

• Example Calculation:

  • Maximum motor speed: 3000 RPM (revolutions per minute) = 50 revolutions per second.

  • Encoder resolution: 10,000 positions per revolution.

  • Total pulses per second at full speed: ( 50 , \text{RPS} \times 10,000 , \text{positions/revolution} = 500,000 , \text{pulses/second} ) or 500 kHz.

• Effect of PN98:

  • With PN98 = 1: The controller must send 500 kHz to achieve full speed (1 pulse = 1 step).

  • With PN98 = 2: The pulse requirement is halved to 250 kHz (1 pulse = 2 steps).

  • With PN98 = 20 (e.g., Thanos AMC setting): Each pulse equals 20 steps, reducing the pulse frequency to 25 kHz at full speed.

The Motion4Sim controller operates with some overhead to ensure reliability. For instance, the factory default pulse frequency is set to 253 kHz when PN98 = 2, providing a slight buffer.

Key Insight

If PN98 is set to 1 but the controller only outputs 250 kHz, the motor will not reach full speed (3000 RPM), as it requires 500 kHz at that setting. Adjusting PN98 effectively reduces the pulse frequency needed while maintaining speed.

PN98 as an Electronic Gearbox

The PN98 parameter functions as an electronic gearbox:

• PN98 = 1: 1 pulse = 1 step (highest resolution, highest pulse frequency).

• PN98 = 20: 1 pulse = 20 steps (lower resolution, lower pulse frequency).

This setting directly impacts the actuator resolution:

• Higher PN98 values reduce the number of pulses needed but decrease the positional precision.

• Lower PN98 values increase precision but demand a higher pulse frequency from the controller.

Importance of PN98 Configuration

The Motion4Sim Servo Controller calculates the required number of steps based on the actuator’s range and the PN98 setting. Proper configuration ensures:

• The motor operates within its safe limits.

• The actuator achieves the desired speed and resolution without damage.

Incorrect PN98 values—whether in the servo driver or the controller software—can lead to performance issues or hardware strain. Thus, aligning PN98 settings between hardware and software is critical.

Conclusion

Understanding the interplay between pulse frequency, PN98, and motor speed is essential for optimizing the Motion4Sim system. The PN98 parameter serves as a powerful tool to balance resolution, speed, and controller workload. We hope this explanation clarifies its significance!