How to seal the cable entry shielding of an HMI (Human Machine Delivery System)?

Shielding and sealing the HMI cable entry point is crucial to preventing interference from coupling through the cable. Ideally, the cable entry point should use a shielded connector, such as a metal-shelled D-Sub, RJ45, or USB connector. The connector's metal shell should achieve a low-impedance overlap with the HMI device housing within a 360-degree range, typically achieved by the connector's built-in metal claws or shielding springs pressing against the metal surface of the housing opening. If the cable itself has a shielding layer but an unshielded connector is used, the cable shielding layer must be reliably connected to the housing at the entry point using a shielding clip or crimp terminal to achieve a 360-degree overlap, avoiding a "pigtail" connection.

For multiple cables or non-standard cable bundles, conductive gaskets or shielding combs can be used. The cable passes through the hole in the center of the gasket; the gasket is compressed, sealing the gap and forming an electrical connection with the cable shielding layer and the housing. In highly demanding applications, a feedthrough filter can be used, combining filtering and shielding functions. The filter housing is soldered or mounted on the housing, and the cable cores pass through the filter. All housing openings at entry points should be as small as possible with smooth, burr-free edges to ensure good contact with connectors or gaskets. Eintech provides a complete solution for shielding and sealing HMI cable entry points, offering a variety of shielded connectors, conductive gaskets, and feedthrough filters.