Differences and Similarities between the NI 2532 and the NI 2532B

Updated Nov 30, 2023

Reported In


  • PXI-2532
  • PXI-2532B
  • Terminal Block

Issue Details

I was looking to purchase an NI 2532 and found that the module has gone end of life and is no longer being sold. What are the differences between the NI 2532 and the NI 2532B?


The NI PXI/PXIe-2532B incorporates an improved connector between the module and terminal block. When the NI PXI/e-2532B is mated to a 264xB terminal block, the combined unit is 100% compatible with an equivalently mated NI PXI/e-2532TB 264x unit; there are no external connectivity or software differences, as only the connectivity between the module and the terminal block changed.

Replacing the module and terminal block together is a drop-in replacement. As seen in the picture, the green boxes represent the similarities between the PXI/PXIe-2532 and the PXI/PXIe-2532B (the backplane connector and the connections on the terminal block) and the red boxes show the differences between the two ( the front panel connector and the ejector handle).

Module Similarities and Differences
  • Same relay architecture: 512-Crosspoint Reed Matrix.
  • Same Driver. (NI PXI/PXIe-2532B and NI PXI/PXIe-2532 are 100% backward compatible with all driver versions)
  • In MAX, both PXI modules appear as "NI PXI-2532".
  • In MAX, both PXIe modules appear as "NI PXIe-2532".
  • Same topology/crosspoint names.
  • Same 100V UL CAT 1 rating.
  • Same pin assignments for IO signals.
  • Same native 1-Wire Sixteen 2x16 Matrices topology (without using Terminal Block accessories).
  • Same simultaneous relay limit.
  • Use front mount Terminal Block accessories (NI TB-264x and NI TB-264xB comparisons are handled later on in this documentation).
    • NI PXI/PXIe-2532B does not have an ejector handle.
    • Different front panel connectors (NI PXI/PXIe-2532B uses ERM8-EM).
    • NI PXI/PXIe-2532B uses equivalent TB-264xB accessories:
    • If a custom (non-NI) terminal block is used:
      • A new custom terminal block is required to support the NI PXI/PXIe-2532B's improved connector.
      • The following pinouts have changed:


    Additional Information

    Terminal Block Similarities and Differences:
    • The NI TB-264x is a front mount Terminal Block accessory for NI PXI/PXIe-2532, while the NI TB-264xB is a front mount Terminal Block accessory for the NI PXI/PXIe-2532B. (The TB-264xB is not compatible with the NI PXI/PXIe-2532, and the TB-264x is not compatible with the NI PXI/PXIe-2532B)
    • Same 0.05" fine pitch ribbon cable headers.
    • Same signal pin assignments.
    • UL Rated for 100V when used with appropriate cables.
    • Same SCB-264x compatibility.
    • Same 0 Ohm or 100 Ω column protection resistors support.
    • Same selectable 100 Ω row protection resistors.
    • TB-264xB supports all Matrix topologies that are supported by TB-264x. TB-264xB adds the TB-2646B which creates a 1-Wire Quad 4x32 Matrix (see the following table):

    • The TB-264xB is 10.7 cm x 2.0 cm x 11.6 cm (The TB-264x is 9.0 cm x 2.0 cm x 8.5 cm).
    • 100 Ω  Row Protection Bypass headers and shunts provided for all models of The TB-264xB.
    • The Row Protection Bypass pins number are in different locations.
       Row Protection Bypass TB-2640B.png  Row Protection Bypass TB-2640.png
    • Change in ribbon cable position.
    • Path resistances increase with the TB-264xB due to larger size and is reflected in the installation instruction sheet
      • Linked is an example of the TB-2640B path resistance listed under "DC Path Resistance"