QQ9937 概覽
A shielded twisted-pair (STP) cable is a balanced transmission medium that uses 90-ohm nominal differential impedance and twisted conductors to cancel common-mode noise, allowing Gigabit and Fast Ethernet signaling to coexist with motor drives, VFDs, and switching power supplies. Within the broader cable hierarchy, Belden 9937 sits in the data-communication / industrial-Ethernet branch, below generic power cables and above unshielded twisted-pair (UTP) Cat5e offerings; it serves as the physical layer that connects PLCs, HMIs, vision systems, and industrial Ethernet switches.
Key features include a 100 MHz bandwidth rating (Cat5e), characteristic impedance of 100 ohms, an overall foil + braid double-shield construction for EMI suppression, and a CM-rated PVC jacket suitable for in-wall and tray installation. Operating temperature range is typically -30C to +75C, and the cable is RoHS compliant per Belden product literature.
The construction pairs 24-25 AWG solid or stranded tinned copper conductors with FPE dielectric, achieving low capacitance (~13 pF/ft typical) and low attenuation at 100 MHz. The aluminum/Mylar foil shield provides 100% coverage against high-frequency interference while the tinned copper braid adds mechanical ruggedness and low-frequency EMI suppression. This dual-shield approach makes the 9937 well-suited for installations adjacent to variable-frequency drives and other switching-noise sources.
Typical applications include industrial Ethernet backbone cabling, PLC-to-PLC communication links, motor-drive feedback signal wiring, factory-floor network drops, and SCADA system interconnects. It is also used in machine vision systems where deterministic data integrity is required.
When routing the 9937, maintain at least 12 inches of separation from VFD power cables and cross power conductors at 90-degree angles when crossing is unavoidable. The overall braid shield must be terminated 360 degrees at both ends to chassis ground using metal backshells to realize the full EMI rejection benefit.
This page synthesizes distributor pricing, drop-in alternatives, and practical installation guidance not found in the manufacturer datasheet, helping engineers select and deploy the correct shielded Ethernet cable for industrial environments.
直接替換替代品，適用於 QQ9937 — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： QQ9937 （相同外形與佔位） — 差異在於 Operating Temperature, Product Type.
7918A
✅ 直接替換📋 參考替代品（不在目錄中）
PCF7936AS
✅ 直接替換聯絡詢價
查看資料表 →7917A
✅ 直接替換📋 參考替代品（不在目錄中）
ETHERLINE Cat5e FD
✅ 直接替換📋 參考替代品（不在目錄中）
GenSPEED 5000
✅ 直接替換📋 參考替代品（不在目錄中）
CS-37P
✅ 直接替換📋 參考替代品（不在目錄中）
QQ9937 規格
| Manufacturer | Belden Inc. |
| Product Type | Fast Ethernet Cat5e Data Single-Ended Cordset |
| Cable Category | Cat5e |
| Conductor Size | 24-25 AWG |
| Conductor Material | Tinned Copper |
| Insulation Material | FPE (Foamed Polyethylene) |
| Shield Type | Aluminum/Mylar Foil + Tinned Copper Braid (overall) |
| Jacket Material | PVC |
| Jacket Rating | CM |
| Nominal Characteristic Impedance | 100 ohms |
| Bandwidth Rating | 100 MHz |
| Capacitance (typical) | 13 pF/ft |
| 工作溫度 | -30C to +75C |
| RoHS 狀態 | Compliant |
| Cable Family | DataTuff / Industrial Ethernet |
QQ9937 standard 腳位配置指南
QQ9937（standard 封裝）的腳位配置。 腳位編號、功能與連接圖定義於製造商資料手冊中。請參閱該手冊以取得確切的封裝尺寸與焊接指引。
無詳細腳位定義資料： QQ9937.
請參閱 資料表 以查看完整腳位配置。
典型應用
QQ9937 適用於 6 應用s: Industrial Ethernet Backbone Cabling, PLC-to-PLC Communication Links, Motor Drive Feedback Signal Wiring, Machine Vision System Networking, Factory Floor Network Drops, SCADA System Interconnects.
Industrial Ethernet Backbone Cabling
The Belden 9937's 100 MHz Cat5e bandwidth and 100 ohm nominal impedance make it ideal for industrial Ethernet backbone cabling connecting PLCs, HMIs, and managed switches in factory automation cells. Its foil + braid double-shield construction rejects EMI from variable-frequency drives and motor contactors that would otherwise corrupt unshielded Ethernet links. Plenum and riser backbone runs up to 100 m are supported without signal integrity loss, and the CM-rated PVC jacket permits installation in cable trays and conduit per NEC Article 800.
推薦
PLC-to-PLC Communication Links
The Belden 9937's 24-25 AWG tinned copper conductors with FPE insulation deliver low attenuation and stable 100 ohm impedance for deterministic PLC-to-PLC Ethernet/IP, PROFINET, and Modbus TCP communication. The braided shield provides robust protection against the high-frequency noise emitted by welding robots and motor starters on the factory floor. Typical installation lengths of 30-80 m between control cabinets achieve error-free operation at 100 Mbps, with the overall foil shield suppressing common-mode interference from VFD power cables routed in parallel trays.
推薦
Motor Drive Feedback Signal Wiring
The Belden 9937's foil + braid overall shield provides the dual-layer EMI rejection required when routing feedback signals from servo drives, encoder lines, and resolver feedback adjacent to high-current motor cables. Its 13 pF/ft typical capacitance minimizes signal distortion on the feedback encoder channel, while the CM-rated PVC jacket allows installation in shared cable trays with proper separation. The cable's -30C to +75C temperature rating covers the operating envelope of typical industrial control cabinets and machine tool enclosures.
推薦
Machine Vision System Networking
The Belden 9937's stable 100 ohm characteristic impedance and low capacitance make it well-suited for GigE Vision and real-time machine vision camera networks where deterministic data delivery is critical. Its shielded construction prevents image data corruption from adjacent strobe lighting inverters and stepper motor drives that emit broadband EMI. The Cat5e 100 MHz bandwidth comfortably supports 1 Gbps vision traffic at standard PoE distances up to 100 m, with the PVC jacket rated for the 24/7 thermal cycling of vision inspection cells.
推薦
Factory Floor Network Drops
The Belden 9937's CM-rated PVC jacket and rugged foil+braid construction make it ideal for the final network drop from overhead cable trays to floor-mounted I/O blocks, HMI panels, and field-mounted Ethernet devices. Its 24-25 AWG conductors support Power over Ethernet (PoE/PoE+) up to 25.5 W per the IEEE 802.3at specification, allowing single-cable deployment of powered sensors and wireless access points. The double-shield design maintains signal integrity when the cable is routed through existing cable trays alongside 480V motor power distribution.
推薦
SCADA System Interconnects
The Belden 9937's industrial-grade shielding and Cat5e bandwidth make it suitable for SCADA RTU-to-master communication links in water treatment, power distribution, and oil & gas supervisory systems. Its 100 ohm impedance matches standard Ethernet PHY requirements, and the overall foil + braid construction provides reliable operation near high-voltage switchgear and transformer installations. The cable's -30C to +75C temperature range covers outdoor enclosure applications when used in conduit, and the CM jacket rating supports installation in control room cable trays per NEC Article 800.
推薦
推薦產品摘要
工程參考資料，適用於 QQ9937 — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 7918A | 7936A | 7917A | ETHERLINE Cat5e FD | GenSPEED 5000 |
|---|---|---|---|---|---|---|
| Package | 1000 ft Reel | 1000 ft Reel - same | 1000 ft Reel - same | 1000 ft Reel - same | 1000 ft Reel - same | 1000 ft Reel - same |
| Brand | Belden | Belden | Belden | Belden | Lapp Group | General Cable |
| Cable Category | Cat5e | Cat6 | Cat5e | Cat5e | Cat5e | Cat5e |
| Bandwidth | 100 MHz | 250 MHz | 100 MHz | 100 MHz | 100 MHz | 100 MHz |
| Conductor Size | 24-25 AWG | 23 AWG | 24 AWG | 24 AWG stranded | 24 AWG | 24 AWG |
| Shield Type | Foil + Braid (overall) | Foil + Braid (overall) | Foil + Braid (overall) | Foil + Braid (overall) | Foil + Braid (overall) | Foil only |
| Jacket Rating | CM (PVC) | CM (PVC) | Outdoor (PE) | CM (PVC) | CM (PVC) | CM (PVC) |
| Impedance | 100 ohm | 100 ohm | 100 ohm | 100 ohm | 100 ohm | 100 ohm |
| Application Focus | Industrial Ethernet backbone | Gigabit Ethernet | Outdoor/burial | Flexible installations | Drag-chain/flexible | General industrial |
主要差異化特點
- Double-shield foil + braid construction for high-EMI environments (對比GenSPEED 5000)
- Same-brand upgrade path to Cat6 bandwidth without re-termination (對比7918A)
- Outdoor-rated same-brand drop-in alternative (對比7936A)
設計說明
Maintain at least 12 inches (30 cm) of separation between Belden 9937 and any VFD motor power cable, or cross power conductors at a 90-degree angle if crossing is unavoidable. Per NEC Article 800 and Belden installation guidelines, parallel runs of unshielded Ethernet cables alongside VFD power cables typically experience bit-error-rate degradation beyond 50 m. The 9937's foil + braid shield significantly improves this margin but does not eliminate the separation requirement.
The overall braid shield MUST be terminated 360 degrees to chassis ground at both ends using metal RJ-45 backshells (such as Stewart Connector SS-39100 series) to realize the full EMI rejection benefit. Pigtail termination with a drain wire alone typically degrades shield effectiveness above 30 MHz, causing CRC errors and link flaps on Gigabit uplinks. Always verify shield continuity with a low-resistance ohmmeter test before commissioning.
When terminating Belden 9937 to a patch panel or keystone jack, follow TIA-568 T568B wiring (most common in North America) and maintain pair twist to within 0.5 inch of the termination point. Excessive untwist increases crosstalk and can push a Cat5e link below margin at 100 MHz. Use a punch-down tool with a cutting blade (Krone or 110-style) and verify each termination with a Fluke DTX or equivalent cable certifier to confirm 100 MHz headroom.
Estimated: For a 90 m run of Belden 9937 at 100 MHz, attenuation is approximately 22 dB per the Cat5e channel limit. Insertion loss margin at the receiver end typically allows for 3-4 connector pairs and a 5 m patch cord. For runs near the 100 m maximum, perform a certification test rather than a simple continuity test to confirm the link supports the desired data rate (100 Mbps Fast Ethernet or 1 Gbps Gigabit Ethernet).
合規資訊
RoHS compliant per Belden product literature. PVC jacket is NOT halogen-free - choose LSZH variants (e.g., Belden 7918A LSZH) for enclosed space or transit applications. NEC CM-rated for in-wall and tray installation per Article 800.
