Use this guide to better understand specifications, differences, and answer common questions about using your NI DAQ terminal block or connector block accessories as signal breakouts. This guide will discuss through NI naming terminology, wiring considerations, signal mapping and pinouts, choosing the right accessory to meet your needs—from low cost to high performance noise reducing, shielded, and more.
This guide is intended to cover accessories 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 Reconfigurable I/O (formerly known as R Series), although some may use similar or the same accessories. It also does not cover legacy or End of Life (EOL) NI DAQ accessories.
If you seek information about a specific connector block or terminal block, 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 accessories come in a variety of shapes, orientations, features, and functionality. This section briefly explains what some of that terminology means. If you want to learn more about a specific accessory, visit the DAQ Accessory Guide Page for your accessory, or its product page.
Use this section to better understand your NI accessory's model name and numbering.
Most SCB, CB, and TBX accessories typically follow the model prefix with a dash and a number indicating the number of pins on its connectors. Common DAQ connectors are -37, -68, and -100 for 37-pin, 68-pin and 100-pin connectors, respectively. Note that some connectors with the same pin count may come in different forms, such as the 68-pin VHDCI or SCSI.
Following the connector pin count, some accessories also include a suffix indicating additional information or functionality. Some of the more common used are:
These terms are used interchangeably in the context of NI DAQ accessories. These accessories act as a breakout box from the pins on your NI DAQ device, featuring screw terminals or BNC connectivity when wiring signals to your system.
For more information on replacement connectors for your NI DAQ accessory, use the information found throughout this guide, as well as NI DAQ Device Custom Cables, Replacement Connectors, and Screws.
When wiring your sensor or other signals into your NI accessory it is important to understand which screw terminal or BNC connectors map back to which terminals or pin numbers on your NI DAQ device. For accessories not covered in the extended information pages from this guide, this guidance generally applies to mapping any NI device's lines to the accessory.
If your device has extended information available in this guide, there may also be additional information on its DAQ Accessory Guide page.
First, it is important to understand that each device may use its own pinout or pin mapping scheme. Some families of devices with the same pin count will use the same numbering and signal combinations, but others may not. There are several resources you can use to find this scheme.
Warning: Always refer to the product documentation for your specific device. Your device may use a completely different pin mapping than what is used in this example.
Navigate to the PCIe/PXI-6361 entry in the NI-DAQmx Device Terminals Help using one of the methods described above to find the following pinout diagram.
In this example, we want to connect our differential signal, AI 0. Since our differential signal requires two wires for signal and COM, we will use the differential signal names designated in parentheses. In this case, pin 68 of the PCIe/PXIe-6361, denoted by AI 0 (AI 0+), will be our signal connection; the COM will connect to AI 8 (AI 0-) at pin 34.
Figure 1: PCIe/PXIe-6361 Pinout with Pin 68 (AI 0+) and Pin 34 (AI 0-) Highlighted
On the SCB-68A we find terminal 68, to which we can wire our AI 0+ signal wire to, and secure through the screw terminal. Similarly, we find terminal 34 to which we can wire our AI 0- signal.
Figure 2: SCB-68A with Terminals 68 and 34 Highlighted
The following table lists the most popular NI DAQ accessories, and provides links to their Accessory Guide Page, if available. General compatibility with NI DAQ devices, modules, and cables are listed on each Accessory Guide page, but a more extensive list can be found in the Multifunction DAQ I/O Compatibility guide. For more information about an accessory not covered in this guide, review the accessory's manual.
|Connectivity||Shielding||Product Page||Accessory Guide||Mounting||Additional Features|
|Screw Terminal||Shielded for high performance noise reduction||SCB-68A1||SCB-68A||DIN Rail2||See guide|
|SCB-100A||SCB-100A||DIN Rail2||See guide|
|TB-2705||-||PXI Module||PXI Mounted|
|TB-2706||-||PXI/PXIe Module||PXI Mounted|
|TB-2621||-||PXI/PXIe Module||PXI Mounted, High Voltage|
|Screw Terminal||Unshielded for low cost applications||CB-68LP||-||Custom Panel||-|
|CB-37F-LP||-||Front mount on module||-|
|CB-37F-HVD||-||DIN Rail||High voltage|
|BNC||Shielded for high performance noise reduction||BNC-2110||-||DIN Rail2||Differential AI|
|BNC-2111||-||DIN Rail2||Single-Ended AI|
|BNC-2115||-||DIN Rail2||AI Extended I/O|
|SMB||Shielded for high performance noise reduction||TB-2708||-||PXI Module||-|
|Custom Connectivity||Shielded signal conditioning enclosure designed for maximum user-defined I/O connectivity and flexibility||CA-1000||-||Rack2||User configurable signal conditioning|
1SCB‑68A and BNC‑2090A are newer designs recommended for all new applications over the SCB‑68 and BNC‑2090.
2DIN rail or rack mount kit sold separately.