Schneider Electric 990NAD23020 Modbus Plus Tap Module

The Schneider Electric 990NAD23020, also cataloged as the 990NAD23020 Modbus Plus Tap, serves as a dedicated hardware component for Modbus Plus signal tapping and branch insertion within Modicon Quantum communication segments. Configured for Modbus Plus link connection in Modicon automation platforms, the Schneider Electric 990NAD23020 (990NAD23020 connection tap) provides direct physical/electrical execution of network node coupling via a single RJ45 interface across Modicon Quantum, Momentum, TSX Micro, and Premium architectures.

Hardware Specifications

Schneider Electric Modbus Plus Tap Signal Integration Behavior

The 990NAD23020 operates as a passive Modbus Plus tap node interface, implementing physical layer branching for token-based network segments. In Modicon architectures, backplane-to-field communication is maintained through deterministic Modbus Plus signaling, where tap insertion preserves impedance continuity across the trunk line.

The RJ45 interface is used as a controlled coupling point for network segmentation without active signal regeneration. Proper installation requires adherence to segment termination rules to prevent reflection-induced communication instability. Signal propagation remains fully dependent on host controller timing and Modbus Plus bus arbitration logic.

Frequently Asked Questions (FAQ)

Q: Does the 990NAD23020 perform signal amplification or regeneration? A: No. The device functions as a passive tap; no signal conditioning, regeneration, or buffering is implemented.

Q: Can the tap be hot-swapped during Modbus Plus operation? A: Hot-swapping is not specified. Installation or removal should be performed with the network in a de-energized state to avoid bus disruption.

Q: Does the RJ45 interface support alternative industrial Ethernet protocols? A: No. The RJ45 connector is mechanically used for Modbus Plus physical connection only and is not protocol-multiplexed.

Field Installation Guidelines

Mount the tap on a standard DIN rail within an IP20-rated enclosure. Maintain separation between Modbus Plus cabling and high-voltage wiring to reduce electromagnetic coupling effects. Ensure shielded cable continuity is preserved through the tap interface.

Cable shields should be grounded at a single reference point per network segment to prevent ground loop formation. Verify correct segment termination at both ends of the Modbus Plus trunk line prior to commissioning. Avoid excessive cable bending radius near the RJ45 interface to maintain connector integrity.