Product Introduction

NI SHC68-68-EPM is a high-performance 68-pin shielded connection cable, serving as an upgraded model for the basic and enhanced versions of the same series. It is primarily designed for low-noise transmission capabilities. The cable is equipped with 68-pin connectors of different specifications at both ends, specifically for connecting NI mainstream DAQ devices with various 68-pin terminal boards, SCXI signal conditioning accessories. The product features a multi-layer graded shielding structure and flame-retardant outer sheath. The impedance has been precisely optimized, enabling stable transmission of analog, digital, counter, and other mixed signals in complex electromagnetic environments. It is suitable for high-precision weak signal acquisition and long-distance wiring scenarios, and offers multiple standard length specifications for selection.

Model Interpretation

SHC represents shielded cable, which is the unified prefix for this series of cables. 68-68 indicates that both ends of the cable are 68-pin connectors. The letter E represents the enhanced shielded design, further enhancing the anti-interference capability. The letter P indicates that the outer sheath of the cable complies with the ventilation duct-level flame-retardant standard. The letter M represents impedance matching optimization, while also strengthening the noise reduction effect and improving the overall signal transmission quality. Technical Specifications

This product contains 68 internal core wires. The analog and digital signals are arranged in twisted pair layout. The signal conductors have a gauge of 30AWG, while the power and ground wires have a gauge of 26AWG. The shielding system is divided into a multi-layer structure. Each pair of analog signals is equipped with an independent shielding layer. The analog area and the digital area are separated and isolated from each other. An additional overall aluminum foil and woven net double shielding is added externally to fully suppress interference and signal crosstalk. The impedance of the analog differential pair is approximately 66 ohms, and the impedance of the digital differential pair is 107 ohms. The capacitance parameters are controlled at a low level. The rated voltage endurance of the cable is 250 volts for continuous voltage, and the insulation resistance under 500 volts DC voltage is not less than 5 megohms. The operating temperature range is from -20 degrees Celsius to 60 degrees Celsius, and the storage temperature range is from -40 degrees Celsius to 70 degrees Celsius. The connector contacts adopt a gold plating process, and the overall insertion and removal service life can reach more than 5,000 times. The cable has the characteristics of wear resistance and anti-bending, and also meets the UL910 flame retardant specification.

Interface and Communication Configuration

One end of the cable is a 68-pin VHDCI male connector, used for connecting NI DAQ devices such as M series, X series, and S series. The other end is a 68-pin SCSI D female connector, which can match external accessories such as SCXI terminal boards, SCB-68, and TBX-68. This cable is an inductive direct connection accessory. All pins are correspondingly connected, and it does not have a protocol conversion function. It can simultaneously transmit single-ended analog signals, differential analog signals, digital input/output signals, and counter encoder signals. When used, no additional hardware switches are required. After connecting the device, it can work normally. It can be used in conjunction with NI-DAQmx driver and the corresponding software development environment to complete data acquisition.

Core Function

The multi-layer hierarchical shielding structure can significantly weaken electromagnetic radiation, radio frequency interference, and line crosstalk, ensuring the transmission accuracy of millivolt-level weak signals. Precise impedance matching design can reduce signal reflection and improve the stability of high-speed signals and long-distance transmission. The overall cable is flame retardant, wear-resistant, and vibration-resistant, suitable for special wiring environments such as industrial control cabinets and ventilation ducts. It has high long-term operational reliability. The integrated core layout can be compatible with the synchronous transmission of various types of signals and meets the requirements of mixed signal acquisition systems. The standard universal interface design is convenient for disassembly and assembly, and can quickly complete the connection and setup of DAQ devices with various terminal boards, signal conditioning modules. Applicable scenarios

High-precision acquisition and transmission of low-level weak sensor signals such as thermocouples, thermoresistors, and strain gauges. It can be combined with the X series high-speed DAQ equipment to complete high-speed synchronous mixed signal testing tasks. Widely used in the SCXI complete signal conditioning system to achieve high-channel-count temperature, pressure, strain, etc. signal acquisition. It can also be used in wiring scenarios where there are interference sources such as frequency converters and motors in industrial sites, as well as distributed testing systems requiring long-distance wiring. At the same time, it can meet the line connection requirements for building equipment and industrial control cabinets that comply with flame-retardant wiring standards.

User and maintenance instructions Instruction Manual

Before performing cable insertion and removal operations, make sure to turn off the power of all connected devices. Do not perform hot-plugging while powered on to avoid damaging the interfaces. When connecting, align the connector with the interface and insert it smoothly, then tighten the fixing screws at both ends to prevent loosening during equipment operation. During wiring, try to keep the cables away from strong power cables and strong interference devices. Avoid sharp corners and bends in the cables, and strictly follow the minimum bending radius requirements. Follow the specifications for system wiring, and it is recommended to ground the shielding layer at one end to avoid interference problems caused by ground loops. Select the appropriate length of cables based on the site distance, and reduce the signal impact caused by excessive wire winding. During maintenance, check the appearance and connection status of the cables and connectors, and check if the outer skin is damaged or the connectors are loose or oxidized. Address any issues promptly. When cleaning, disconnect all power supplies, use a dust-free soft cloth to wipe the surface of the cables and connectors. Use isopropyl alcohol to gently wipe the contact stains, and allow it to dry completely before resuming use. When cables are left idle for a long time, arrange and coil them neatly, maintain an appropriate coil diameter, and place them in a cool and dry place to avoid being squeezed by heavy objects, exposed to direct sunlight, or subjected to severe pulling.