Network Example

The image below presents a network and power layout of an example JCS system:

2link example

The example is a fictitious two link robot. The base link houses thermal management and braking chopper devices and directly connects to the host computer. Link 0 has encoder devices to measure joint position and torque and two motor controllers, encoders and motors. These might be yaw and pitch motors. Link 1 has encoder devices to measure joint position and torque and one motor controller, encoder and motor. This might be to actuate the last link in the chain. Link 1 also has an analog interface for measuring some quantities and might also interface to a ground contact switch or pressure sensor.

In this example we see the following:

  • The host computer communicates with three joint controller devices over the high speed bus.
  • The joint controllers communicate with the remaining devices over the lower speed JCS net bus.
  • Each joint controller has different ports populated, with each port having different quantities of devices chained from it.
  • Only power devices and joint controllers require 12V. Power to smaller devices is provided via the JCS network connections.

Notes:

  • All dev_joint_controller child devices at the physical end of the network chain require a loopback connector.
  • The Ethercat bus does not require a loopback connector.
  • Unpopulated dev_joint_controller ports do not require loopback connectors.
  • All dev_joint_controller ports do not have to be populated. If required, no dev_joint_controller ports can be populated.
  • It is not required to populate dev_joint_controller ports in order.