How to correctly connect the shielded ground of the motion controller MC

Properly connecting the shielding ground of the motion controller (MC) is a prerequisite for ensuring the effectiveness of the cables and local shielding. The cable shielding should be connected to the housing ground at the entrance to the controller housing using a 360-degree low-impedance connection via the connector's metal housing or shielding clip. "Pigtail" connections should be strictly avoided. Local shielding on the PCB should be soldered to the internal ground plane via a uniformly distributed array of vias, with the via spacing less than 1/20th of the wavelength of the highest frequency of interest. If the shielding contains analog circuitry, it should be connected to analog ground.

The shielding of isolation transformers or optocouplers should be connected to the static ground between the primary and secondary windings. In multi-level shielding systems, the inner shield should be connected to the circuit ground, and the outer shield to the housing ground. After connection, the resistance between the shielding termination and the housing should be measured to ensure it is in the milliohm range. For high-frequency applications, shielding effectiveness testing can be performed to verify the effectiveness of the connection method. It is also necessary to ensure that the shielding connection does not accidentally introduce new ground loops.