Table Of Contents

PXIe-2531 Specifications

    Last Modified: April 19, 2017

    This document lists specifications for the PXIe-2531 512-crosspoint, 1-wire matrix. All specifications are subject to change without notice. Visit for the most current specifications.

    PXIe-2531 Specifications

    Specifications characterize the warranted performance of the instrument under the stated operating conditions. Data in this document are Specifications unless otherwise noted.

    Typical Specifications are specifications met by the majority of the instrument under the stated operating conditions and are tested at 23 °C ambient temperature. Typical specifications are not warranted.

    All voltages are specified in DC, ACpk, or a combination unless otherwise specified.


    To ensure the specified EMC performance, operate this product only with shielded cables and accessories.


    The protection provided by the PXIe-2531 can be impaired if it is used in a manner not described in this document.


    Refer to the NI Switches Help at for detailed topology information.


    1-wire 4 × 128 matrix

    1-wire 8 × 64 matrix

    1-wire dual 4 × 64 matrix

    1-wire dual 8 × 32 matrix

    Input Characteristics

    Maximum switching voltage


    60 VDC, 30 VACrms


    60 VDC, 30 VACrms, CAT I

    Measurement Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS voltage. MAINS is a hazardous live electrical supply system that powers equipment. This category is for measurements of voltages from specially protected secondary circuits. Such voltage measurements include signal levels, special equipment, limited-energy parts of equipment, circuits powered by regulated low-voltage sources, and electronics.


    Do not connect the PXI/PXIe-2531 to signals or use for measurements within Measurement Categories II, III, or IV.


    Measurement Categories CAT I and CAT O are equivalent. These test and measurement circuits are not intended for direct connection to the MAINS building installations of Measurement Categories CAT II, CAT III, or CAT IV.

    Maximum current (switching or carry, per channel)

    0.5 A


    The maximum switching power is limited by the maximum switching current and the maximum voltage, and must not exceed 10 W.

    Maximum switching power (per channel)

    10 W

    DC path resistance


    <1 Ω


    ≥2 Ω

    Open channel

    ≥1 * 109 Ω


    DC path resistance typically remains low for the life of the relay. At the end of relay life, the path resistance rapidly rises above 2 Ω. Load ratings apply to relays used within the specification before the end of relay life.

    Thermal EMF


    <50 µV, typical


    <20 µV, typical

    RF Performance Characteristics

    Bandwidth (-3 dB, 50 Ω termination), 1-wire row/column

    ≥20 MHz, typical

    Crosstalk (50 Ω termination), channel-to-channel

    10 kHz

    <-70 dB, typical

    100 kHz

    <-70 dB, typical

    1 MHz

    <-58 dB, typical

    10 MHz

    <-38 dB, typical

    Isolation (50 Ω termination), open channel

    10 kHz

    >91 dB, typical

    100 kHz

    >71 dB, typical

    1 MHz

    >51 dB, typical

    10 MHz

    >32 dB, typical

    Dynamic Characteristics

    Simultaneous drive limit


    40 relays

    PXI Express

    64 relays

    Relay operate time

    0.25 ms


    Certain applications may require additional time for proper settling.

    Release time

    0.25 ms

    Relay life (no load)


    1 * 109 cycles, typical

    Electrical (resistive, <10 pF load)

    10 V, 100 mA

    1 * 107 cycles, typical

    20 V, 500 mA

    5 * 106 cycles, typical

    100 V, 10 mA

    1 * 105 cycles, typical


    Reed relays are highly susceptible to damage caused by switching capacitive and inductive loads. Capacitive loads can cause high inrush currents while inductive loads can cause high flyback voltages. The addition of appropriate resistive protection can greatly improve contact lifetime. For more information about adding protection circuitry to a capacitive load, visit and enter the Info Code relaylifetime. For information about inductive loads, enter the Info Code relayflyback.


    The relays used in the PXIe-2531 are field replaceable.

    Trigger Characteristics

    Input trigger


    PXI trigger lines 0 to 7

    Minimum pulse width

    150 ns


    The PXIe-2531 can recognize trigger pulse widths <150 ns if you disable digital filtering.

    Output trigger


    PXI trigger lines 0 to 7

    Pulse width

    Programmable (1 µs to 62 µs)

    Physical Characteristics

    Relay type



    NI advises against installing reed relay modules directly adjacent to an embedded controller with a magnetic hard drive because of the sensitivity of reed relays and the possibility of interference.

    Relay contact material


    I/O connectors

    2, 150 pos, Samtec ERM8 series

    Power requirement


    10 W at 5 V, 2 W at 3.3 V

    PXI Express

    15 W at 12 V, 2 W at 3.3 V

    Dimensions (L × W × H)

    3U, one slot, PXI/cPCI module, 21.6 × 2.0 × 13.0 cm (8.5 × 0.8 × 5.1 in.)


    454 g (1 lb)


    Operating temperature

    0 °C to 55 °C

    Storage temperature

    -40 °C to 70 °C

    Relative humidity

    5% to 85%, noncondensing

    Pollution Degree


    Maximum altitude

    2,000 m

    Indoor use only.

    Shock and Vibration

    Operational Shock

    30 g peak, half-sine, 11 ms pulse (Tested in accordance with IEC 60068-2-27. Test profile developed in accordance with MIL-PRF-28800F.)

    Random Vibration


    5 Hz to 500 Hz, 0.3 grms


    5 Hz to 500 Hz, 2.4 grms (Tested in accordance with IEC 60068-2-64. Nonoperating test profile exceeds the requirements of MIL-PRF-28800F, Class 3.)

    Compliance and Certifications


    This product is designed to meet the requirements of the following electrical equipment safety standards for measurement, control, and laboratory use:

    • IEC 61010-1, EN 61010-1
    • UL 61010-1, CSA 61010-1

    For UL and other safety certifications, refer to the product label or the Online Product Certification section.

    Electromagnetic Compatibility

    This product meets the requirements of the following EMC standards for sensitive electrical equipment for measurement, control, and laboratory use:

    • EN 61326-2-1 (IEC 61326-2-1): Class A emissions; Basic immunity
    • EN 55011 (CISPR 11): Group 1, Class A emissions
    • AS/NZS CISPR 11: Group 1, Class A emissions
    • FCC 47 CFR Part 15B: Class A emissions
    • ICES-001: Class A emissions

    In the United States (per FCC 47 CFR), Class A equipment is intended for use in commercial, light-industrial, and heavy-industrial locations. In Europe, Canada, Australia and New Zealand (per CISPR 11) Class A equipment is intended for use only in heavy-industrial locations.


    Group 1 equipment (per CISPR 11) is any industrial, scientific, or medical equipment that does not intentionally generate radio frequency energy for the treatment of material or inspection/analysis purposes.


    For EMC declarations and certifications, and additional information, refer to the Online Product Certification section.

    CE Compliance

    This product meets the essential requirements of applicable European Directives, as follows:

    • 2014/35/EU; Low-Voltage Directive (safety)
    • 2014/30/EU; Electromagnetic Compatibility Directive (EMC)

    Online Product Certification

    Refer to the product Declaration of Conformity (DoC) for additional regulatory compliance information. To obtain product certifications and the DoC for this product, visit, search by model number or product line, and click the appropriate link in the Certification column.

    Environmental Management

    NI is committed to designing and manufacturing products in an environmentally responsible manner. NI recognizes that eliminating certain hazardous substances from our products is beneficial to the environment and to NI customers.

    For additional environmental information, refer to the Minimize Our Environmental Impact web page at This page contains the environmental regulations and directives with which NI complies, as well as other environmental information not included in this document.

    Waste Electrical and Electronic Equipment (WEEE)
    EU Customers  

    At the end of the product life cycle, all NI products must be disposed of according to local laws and regulations. For more information about how to recycle NI products in your region, visit


    National Instruments符合中国电子信息产品中限制使用某些有害物质指令(RoHS)。关于National Instruments中国RoHS合规性信息,请登录。(For information about China RoHS compliance, go to

    Recently Viewed Topics