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Hardware

CAN FD

CAN FD connects one or more PULSE actuators to a computer through a USB-to-CAN adapter.

Required hardware

  • one Pulsar USB-to-CAN adapter;
  • one USB cable for the adapter;
  • CAN cables with compatible 3-pin Molex PicoBlade connectors;
  • one CAN-Terminator at each physical end of the bus;
  • powered, securely mounted actuators with unique addresses.

See Electrical interfaces for connector and pinout details.

Wire one actuator

  1. Connect the adapter to the computer.
  2. Put one CAN-Terminator on one adapter CAN port.
  3. Connect the other adapter CAN port to either actuator CAN port.
  4. Put the second CAN-Terminator on the actuator's unused CAN port.

Single-actuator CAN network

CAN ports are bidirectional. The CAN-Terminators must remain at the two physical ends of the complete bus.

Discover addresses

Install Pulsar Python SDK, then scan the bus:

pulsar-cli scan

The default scan range is 16–255. Valid actuator CAN addresses are 16–16382.

Add actuators

Daisy-chain additional actuators and keep only two CAN-Terminators, one at each physical end. Every actuator on one PcpOverCan domain must have a unique address.

More than eight registered actuators is allowed, but is not recommended for stability and to get the most performance. Request only the telemetry required by the application and use the CAN bus utilization tool to estimate your utilization before increasing actuator count or rates.

Planning multiple buses

Actuators on one CAN FD bus share its communication capacity. For larger systems, consider distributing actuators across independent buses, each with its own compatible USB-to-CAN adapter, subject to host USB-port availability. Plan each bus separately for command and telemetry traffic, physical wiring, and electrical loading.

Use the CAN bus utilization tool to estimate communication utilization. This estimate does not establish electrical compatibility or guarantee real-time performance. Each independent bus must retain termination at both physical ends; see Wire one actuator for the termination arrangement.

A computing unit connects over USB to two CAN-to-USB adapters, each serving a separate linear CAN bus with actuator nodes and termination at both ends; photos show adapter and termination hardware.

The shown node count and addresses are examples, not a product limit. The exposed adapter board is shown for identification only; do not remove an enclosure or operate a board unenclosed to avoid interference at high communication speeds.

Data-rate switching

CAN FD can use a 5 Mbit/s data phase. Treat bit-rate switching as a bus-wide configuration: all devices on the bus must be compatible and configured consistently.

Troubleshooting

Continue with the CAN FD quickstart or the Pulsar Python SDK physical-CAN guide for software setup.

Adapter not detected

  • reconnect the adapter;
  • try another USB cable or port;
  • pass the serial port explicitly;
  • check operating-system serial permissions.

No actuator found

  • confirm actuator power;
  • check CAN_H, CAN_L, and ground wiring;
  • verify both CAN-Terminators;
  • try a smaller scan range around known addresses;
  • replace worn-out cables.

If the problem persists, contact support.