Use this guide to better understand specifications and differences, and answer common questions about using NI cables with your DAQ devices and modules. This guide discusses NI naming terminology, repairing or making a custom cable, addressing noise and unexpected signals, finding information such as signal mapping and pinouts, and choosing the right cable to meet your needs—from low cost ribbon cables to high performance noise reducing, shielded, and more.
This guide is intended to cover cables designed for use with NI DAQ devices, and their use cases. It does not cover use with other NI product families such as Digital Instruments (formerly HSDIO), C Series, or R Series, although some may use similar or the same cables. It also does not cover legacy or End of Life (EOL) NI DAQ cables.
If you seek information about a specific cable, NI recommends that you first review this page and its more general information to better understand the product offerings, and then jump to the page for your specific model.
NI cables come in a variety of options and functionality. This section briefly explains what some of those acronyms and other terminology means. To learn more about a specific cable, visit the DAQ Cable Guide Page for your cable, or its product page.
Use this section to better understand your NI accessory's model name and numbering.
Most cable models will include two numbers, indicating the pin counts of the mating connectors found on each end.
Use this section to help identify the connector type found on your cable. To create a custom cable or for more information on replacement connectors, jackscrews or jacksockets for your NI DAQ cable, use the information found throughout this guide, as well as NI DAQ Device Custom Cables, Replacement Connectors, and Screws, which includes part numbers. You can also use this pinout or mapping information when creating a custom PCB breakout fixture or terminal block.
An improvement on a SCSI connector allowing a smaller footprint and fewer bent pins during connection. Features 0.8 mm pin spacing. Typically found on the device or module end. Most VHDCI cable models begin with SHC or RC ("C" indicating compact). Note: Many cables feature a SCSI 0.050 D-Type on the accessory end. Learn more about common cables that use the 68-pin VHDCI connector to mate with DAQ devices or modules.
Note: Connector image is oriented differently than pinout below.
|68-Position Cable Connector Plug (Male)|
Industry standard SCSI connector standard featuring 0.050 pin spacing. Found on the device or module end or the accessory end. Most SCSI cable models begin with SH or R. Learn more about common cables that use the 68-pin SCSI 0.050 D-Type connector to mate with DAQ devices or modules.
Note: Connector image is oriented differently than pinout below.
|100-Position Cable Connector Plug (Male)||68-Position Cable Connector Receptacle (Female)|
Industry standard D-Sub (DSUB) connector, sometimes used for higher voltage ratings. Most D-Sub cable models begin with SH or DB.
|37-pin D-Sub Cable Connector Plug (Male)|
NI offers an array of NI DAQ cable options to meet the needs of your application. From basic unshielded ribbon cables up to cables, such as SHC-68-68-EPM, featuring specifically designed shielding and twisted pairs to deliver the optimal performance. This section explains two important features that greatly affect signal quality, shielding and twisted pairs, and why you should care about them.
Figure 1: Example cross-section of cable with shielding and twisted pairs.
Shielded cable assemblies are designed and manufactured to provide maximum performance and noise immunity. This thin layer of metallic shielding reduces electromagnetic interference from other signals on the cable, and also from external noise sources. To achieve this, the entire cable, and sometimes groupings of conductors, are enclosed in shielding
NI also sells unshielded ribbon cables for low-cost applications or for environments and applications where noise and crosstalk are not a concern.
Some twisted pairs are optimized for differential analog input signals through the use of positive (+) and negative (-) signal pairs. Noise or interference will appear on both lines, and thus the common-mode signal can be canceled by the differential ADC. Other pairs may be twisted with a ground wire or drain wire. By adding twisted pairs electromagnetic interference, noise, and crosstalk can be reduced.
Many NI shielded cable assemblies also feature twisted pairs for improved noise performance. Different shielded cables are recommended for different devices and applications, based on signal pairings and groupings, to give the best performance.
Are you having trouble getting a good reading or is your system not working as expected? Experiencing noise, interference, unexpected or unwanted readings can originate from many parts of your system. Choosing the proper cable, and ensuring you follow best wiring practices, will help ensure the best reading.
When mounting in a rack or enclosure or otherwise routing your cable, it is important to know how much you can bend the cable without damaging it. NIfollows 2014 NEC Section 300.34 Conductor Bend Radius and 300.24 Bending Radius standards to define the bend radius for cables. Many DAQ Multifunction I/O cables are assembled as multi-conductor cables with individually shielded conductors. Per these standards, the bend radius is then defined as 12 times the cable diameter. Cable diameter is specified in the dimensional drawings for the cable, and is also listed on the cable guide page for your cable. Use the major diameter specification for the calculation. For example, the SHC-68-68-EPM specifies a major diameter of 0.540". As such the resulting bend radius would be 12*(0.540") = ~6.5". Note that other NI cables may specify a different bend radius, due to their construction.
The following table lists the most popular NI DAQ cables, and provides links to their Cable Guide page, if available. Use this table as a starting point when selecting or picking cable options for your application. General compatibility with NI DAQ devices, modules, and cables are listed on each Cable Guide page, but a more extensive list can be found in the Multifunction DAQ I/O Compatibility guide.
|Shielding||Features||Model||Device Connector||Accessory Connector||Cable Guide||Dimensional Drawing|
|For high voltage||DB37M-DB37F-EP||D-Sub||D-Sub||-||Link|
|For custom breakouts with VHDCI connectors||SHC68-C68-EPM||VHDCI||VHDCI||Link||-|
|Conversion, to 68-pin||SH100-68-68||SCSI||SCSI||-||Link|
|Unshielded||Low cost, ribbon cable||RC68-68||VHDCI||SCSI||Linfk||-|
|Low cost, ribbon cable, conversion, to 50-pin||R68-50||SCSI||IDC||-||Link|
1 When used with DAQ devices and modules, the VHDCI end is connected to the device or module and SCSI end is connected to the accessory.
2 The SH100M-100M Flex cable was formerly named SH100-100-F.