How to avoid signal crosstalk in industrial servo multi-interface systems?

When servo devices integrate multiple interfaces (such as EtherCAT, CAN, encoders, and analog signals), avoiding signal crosstalk requires design considerations from three aspects: spatial arrangement, frequency domain, and grounding. E-Tech Electronics' avoidance measures include:

1) Spatial isolation: On the PCB layout, place circuit modules for different interfaces in separate zones, separated by grounding shields or power planes. Interface connectors should also be distributed as dispersedly as possible on the chassis.

2) Frequency domain isolation: Allocate different frequency band resources to interfaces with different speeds; for example, separate low-speed DI/DO and high-speed communication wiring on different board layers.

3) Grounding management: Provide independent grounding paths for noisy interfaces (such as power interfaces) and sensitive interfaces (such as encoders), ultimately converging at a single point.

4) Cable separation: Group cables for different interfaces within the cabinet, maintaining distance or using shielding partitions.

Through these measures, crosstalk from high-speed communication to sensitive circuits such as analog sampling can be reduced by more than 30dB, ensuring that each interface does not interfere with others when operating at full load.