Modbus Plus Network Trunk Cable 490NAA27103 by Schneider Electric

Product Overview

The Schneider Electric 490NAA27103​ is a premium, factory-manufactured trunk cable specifically designed for the reliable installation of Modbus Plus (MB+) industrial networks. This cable serves as the essential communication backbone, physically connecting all nodes—such as Quantum/Momentum PLCs, HMIs, bridges, and other compatible devices—within a Modbus Plus network segment. The Schneider Electric 490NAA27103​ is not a generic cable; it is a purpose-built, 1000-foot reel of high-performance, shielded data cable that meets the exacting electrical specifications required for the 1 Mbps token-passing protocol of Modbus Plus. It ensures consistent impedance, low signal attenuation, and robust noise immunity over extended distances, which are critical for maintaining data communication integrity in electrically noisy industrial environments. The use of this certified trunk cable is a fundamental requirement for building a stable and high-performance MB+ network, as it directly impacts the network’s maximum segment length, the number of allowable nodes, and overall reliability.A key aspect of the 490NAA27103​ is its construction to a recognized industrial cable standard, often Belden 9842 or equivalent, which features two individually shielded twisted pairs within an overall foil/braid shield and a durable outer jacket. One twisted pair is dedicated to the differential data signals (Data A and Data B), while the other pair is used for the network’s DC power supply that can be used to power terminators or other network components. This design provides superior protection against electromagnetic interference (EMI) and radio frequency interference (RFI), which are common causes of communication errors and network instability. By deploying the genuine Schneider Electric 490NAA27103​ cable, system integrators and plant engineers lay a robust physical foundation for their control network, minimizing the risk of intermittent faults, data corruption, and costly downtime associated with subpar cabling. It represents the recommended and reliable choice for both new installations and upgrades to existing Modbus Plus infrastructures where network performance and longevity are paramount.

Technical Specifications

Main Features and Advantages

Optimized electrical performance for reliable MB+ networks: The Schneider Electric 490NAA27103​ is engineered with precise electrical characteristics that are crucial for the 1 Mbps signaling of Modbus Plus. The controlled 120-ohm impedance of the data pair minimizes signal reflections, which can cause data errors, especially at the network’s maximum segment length. Its low capacitance per unit length helps preserve the sharp rise and fall times of the digital signals, preventing them from becoming “smeared” and indistinguishable over long distances. This ensures that the token can be passed reliably between all 32 possible nodes on a segment and that peer-to-peer messaging occurs without corruption. Using generic or unspecified cable can lead to impedance mismatches and high capacitance, resulting in an unstable network that suffers from intermittent dropouts, token loss, and difficult-to-diagnose communication faults. The 490NAA27103​ eliminates this guesswork, providing guaranteed performance.Superior noise immunity and robust construction: Industrial environments are electrically hostile, filled with sources of interference like variable frequency drives, motor starters, and welding equipment. The multi-layer shielding of the 490NAA27103​ cable is its primary defense. Each individually shielded twisted pair protects against crosstalk between the data and power conductors, while the overall foil/braid shield protects the entire cable from external EMI/RFI. The drain wire ensures the shield can be effectively grounded at one point, channeling interference away from the sensitive data lines. This comprehensive shielding strategy ensures that the differential data signals (Data A and Data B) remain clean and decodable by network adapters. Furthermore, the durable PVC outer jacket resists abrasion, oils, and chemicals commonly found in factories, protecting the internal conductors from physical damage during and after installation. This combination of electrical and mechanical robustness makes the Schneider Electric 490NAA27103​ a long-term, reliable asset for the plant floor.