Technical Specifications

• Product Model: 990NAD23000
• Manufacturer: Schneider Electric (Modicon)
• Product Type: IP20 Modbus Plus Junction Box / T-Tap
• Network Protocol: Modbus Plus (MB+)
• Interfaces: 3-port design (2 for trunk in/out, 1 for device drop)
• Terminal Type: Screw terminal blocks for secure wiring
• Termination: Built-in switchable 120-ohm resistor
• Enclosure Rating: IP20 (for panel/cabinet mounting)
• Weight: 0.23 kg (0.51 lb)
• Compliance: RoHS compliant, Green Premium certified

 

Main Features and Advantages

Centralized Connection Point

The junction box provides organized screw terminals for trunk in, trunk out, and device drop connections. This eliminates unreliable vampire taps or field-made splices, preserving the integrity of the main shielded trunk cable and simplifying node installation or removal.

Integrated Termination Resistor

To ensure signal integrity on the high-speed (1 Mbps) MB+ network, the unit includes a built-in 120-ohm terminating resistor. A DIP switch or jumper allows technicians to enable or disable termination as needed, absorbing signal energy and preventing data errors caused by reflections.

Rugged and Maintainable Design

Housed in a corrosion-resistant plastic enclosure, the device protects connections from dust and accidental contact. Its DIN-rail mountable form factor allows for easy integration into existing control panels and facilitates quick troubleshooting.

Application Field

The 990NAD23000​ is essential in any facility utilizing Modicon PLCs with Modbus Plus networking. It is widely used in process industries (water/wastewater, oil & gas), discrete manufacturing (automotive, packaging), and infrastructure (power generation, HVAC) to connect controllers, drives, HMIs, and gateways onto a reliable, daisy-chained communication backbone.

Related Products

• 490 NAA 271 xx: Standard shielded twisted-pair trunk cables used to link multiple 990NAD23000​ junction boxes together.
• 990 NAD 211 xx: Drop cables that connect a specific device (PLC, HMI) to the drop port of the junction box.
• AS-MBKT-085: Non-terminated in-line connector, an alternative to the 990NAD23000​ for mid-segment connections where no device drop is required.
• AS-MBKT-185: In-line connector with built-in termination, used at the ends of a segment if a full junction box is not needed.
• 043 509 383: Specialized wiring tool recommended for properly stripping and connecting wires to the junction box terminals.