Product Introduction

NI SH68-68-EP is a 68-pin SCSI D-type shielded I/O cable specifically designed for connecting NI E/S/B/M series DAQ devices with 68-pin terminal boards / signal conditioning accessories, for high integrity transmission of analog, digital, and counter signals. It has multi-layer shielding to resist interference and provides a reliable link for weak signal / high-speed acquisition in laboratories and industrial sites. The part number is 184749-01 (1 meter), and there are also 2/5/10 meters available as options. It has been replaced by SH68-68-EPM but is still compatible for supply.

Model Interpretation

SH: Shielded, shielded cable.

68-68: Both ends are 68-pin 0.050-inch spacing SCSI D-type female connectors. NI.

EP: Enhanced Performance, enhanced performance shield, different from the ordinary SH68-68, with stronger noise reduction and anti-interference capabilities. Technical Specifications

Conductor and Shielding

Core Count: 68 cores, including analog twisted pair, digital twisted pair, power/ground wire NI.

Wire Gauge: Analog pair 28AWG, digital pair 30AWG, power/ground wire 26AWG NI.

Structure: Analog pair independent shielding + overall aluminum foil + woven mesh triple shielding; digital pair twisted pair + overall shielding NI.

Impedance: Analog differential pair 66±8Ω, digital differential pair 107Ω NI.

Capacitance: Analog pair ≤ 25.5pF/ft, digital pair 14.5pF/ft NI.

Voltage Rating: 300Vrms, insulation resistance ≥ 5MΩ@500VDC.

Physical and Environmental

Length: 1 meter (184749-01), available in 2/5/10 meters.

Temperature: Operating -20℃～60℃, Storage -40℃～70℃.

Coating: Flame-retardant PVC, compliant with UL910, wear-resistant and resistant to bending.

Connector: Gold-plated contacts (≥30μin), plug-in life ≥1000 times.

Interface and Communication Configuration

Both Ends Interface: 68-pin SCSI D-type female connector (0.050 inch spacing), screw-fixed anti-loosening NI.

Adapting Equipment: E series (60xxE), S series (61xx), B series, USB M series (62xx) DAQ cards NI.

Adapting Accessories: SCB-68, TBX-68, CB-68LPR, SCXI-1377/1378 terminal boards.

Communication Characteristics: Passive full-pin direct connection, supports differential/single-ended analog, digital I/O, counter/encoder signal parallel transmission; no protocol conversion, plug-and-play NI.

Core Function

Enhanced Anti-interference: Triple shielding structure suppresses EMI/RFI and crosstalk, ensuring microvolt-level weak signal accuracy NI.

Multi-signal Compatibility: Simultaneous transmission of analog, digital, counter signals, suitable for mixed signal acquisition systems NI.

High-reliability Connection: Gold-plated contacts + screw fixation, resistant to vibration, resistant to plugging and unplugging, suitable for long-term operation in industrial environments.

Long-distance Stability: Signal attenuation is small within 5 meters, suitable for remote connection of distributed sensors. Applicable scenarios

DAQ connection to terminal board: E/S/M series DAQ cards are connected to 68-pin connector boxes such as SCB-68/TBX-68 from National Instruments.

Front-end of SCXI system: DAQ is directly connected to SCXI-1377/1378 terminal boards to build a high-channel-count temperature / strain acquisition system.

High-precision measurement of weak signals: Anti-interference transmission of low-level signals such as thermocouples, RTDs, and strain gauges from National Instruments.

Mixed signals in industrial field: Synchronous acquisition of multi-channel analog + digital + counter, such as motor testing and equipment monitoring from National Instruments.

User and maintenance instructions Instruction Manual

Power-off connection/disconnection: Before connecting or disconnecting, turn off the power supply of the DAQ and peripheral devices to avoid damaging the interface due to hot plugging.

Connection guidelines: Insert the device smoothly into the interface, tighten the fixing screws at both ends to prevent loosening due to vibration; avoid pulling the cables.

Grounding requirements: Single-ended grounding of the shielding layer (at the DAQ end), to avoid ground loop interference; differential transmission of analog signals is preferred for NI.

Cabling considerations: Keep away from interference sources such as strong electrical cables and frequency converters; the bending radius should be ≥ 8 times the outer diameter of the cable to avoid sharp corner bending.

Maintenance instructions

Environmental management: Maintain dryness and ventilation, control the temperature and humidity within the rated range, and keep away from dust, corrosive gases and strong electromagnetic sources.

Regular inspection: Check every quarter if the connectors are loose or oxidized, and if the outer skin of the cables is damaged; clean the dirt on the connectors with isopropyl alcohol, dry them and use them.

Cleaning operation: Wipe the cables and connectors with a dust-free soft cloth during power-off; do not allow liquids to directly contact the interfaces.

Storage guidelines: When not in use, coil the cables (diameter ≥ 15cm), store them in a cool and dry place, and avoid heavy pressure, direct sunlight and violent vibration.