Table Of Contents

PXI-2520 Specifications

    Last Modified: April 19, 2017

    This document lists specifications for the PXI-2520. All specifications are subject to change without notice.


    Warranted specifications describe the performance of a model under stated operating conditions and are covered by the model warranty.

    Characteristics describe values that are relevant to the use of the model under stated operating conditions but are not covered by the model warranty.

    • Typical specifications describe the expected performance met by a majority of the models.
    • Nominal specifications describe parameters and attributes that may be useful in operation.

    Specifications are Typical unless otherwise noted.


    Specifications are valid at 23 °C unless otherwise noted.

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


    The protection provided by the PXI-2520 can be impaired if it is used in a manner not described in this document.

    Cleaning the Module

    Clean devices and terminal blocks by brushing off light dust with a soft, nonmetallic brush. Remove other contaminants with a soft, lint-free, dampened cloth. Do not use detergent or chemical solvents. The unit must be completely dry and free from contaminants before returning to service.



    This module is rated for Measurement Category I and intended to carry signal voltages no greater than 150 V. This module can withstand up to 800 V impulse voltage. Do not use this module for connection to signals or for measurements within Categories II, III, or IV. Do not connect to MAINS supply circuits (for example, wall outlets) of 115 V AC or 230 V AC. Refer to the Read Me First: Safety and Electromagnetic Compatibility document for more information about measurement categories.


    When hazardous voltages (>42.4 Vpk/60 V DC) are present on any channel, safety low-voltage (≤42.4 Vpk/60 V DC) cannot be connected to any other channel.


    The switching power is limited by the maximum switching current, the maximum voltage, and must not exceed 60 W, 62.5 VA.

    Input Characteristics

    Maximum switching voltage


    150 V


    150 V, CAT I

    Maximum switching current

    2.0 A (per channel)

    Maximum carry current

    2.0 A (per channel)

    Maximum switching power

    60 W, 62.5 VA (DC to 60 Hz) (per channel)

    Simultaneous channels at maximum current (≤43 °C)


    Minimum switching conditions

    20 mV/1 mA


    Switching inductive loads (for example, motors and solenoids) can produce high voltage transients in excess of the module’s rated voltage. Without additional protection, these transients can interfere with module operation and impact relay life. For more information about transient suppression, visit and enter the Info Code relayflyback.

    DC path resistance


    <0.5 Ω


    ≥1.0 Ω


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

    Thermal EMF (typical at 23 °C)

    12 µV

    Bandwidth (-3 dB, typical at 23 °C, 50 Ω termination)

    ≤35 MHz

    Crosstalk (typical at 23 °C, 50 Ω termination), Channel-to-channel

    10 kHz

    ≤-80 dB

    100 kHz

    ≤-60 dB

    Isolation (typical at 23 °C, 50 Ω termination), Open channel

    10 kHz

    ≥80 dB

    100 kHz

    ≥60 dB

    Derating PXI-2520 Load at >43 °C

    To verify you are operating the PXI-2520 within supported 2-wire derating conditions, complete the following steps:
    1. Use the following equation to calculate the load: Load = Channels 1 × ( Current 1 ) 2 + Channels 2 × ( Current 2 ) 2 + ... + Channels n × ( Current n ) 2 where Channels is the number of channels that simultaneously carry a signal, Current, for 1, ... , n.
    2. Verify that the load at your ambient operating temperature falls within the shaded region of the following figure.
      Module Load Derating
      Figure 1. PXI-2520 Load Derating

    Examples of Load Derating

    The following examples calculate supported derating conditions for the PXI-2520.

    Example 1

    ( 30 × 1.7 2 ) + ( 10 × 1.5 2 ) = 109.2 A 2 × c h a n n e l s
    where 30 channels carry 1.7 A
      10 channels carry 1.5 A

    You can use the module at ambient temperatures between 0 °C and 47 °C.

    Example 2

    ( 25 × 1.55 2 ) + ( 5 × 2.0 2 ) = 80.06 A 2 × c h a n n e l s
    where 25 channels carry 1.55 A
      5 channels carry 2.0 A

    You can use the module at ambient temperatures between 0 °C and 55 °C.

    Dynamic Characteristics

    Relay operate time


    1 ms


    3.4 ms

    Simultaneous drive limit

    40 relays

    Expected relay life


    1 × 108 cycles

    Electrical (resistive)

    30 V, 1 A

    5 × 105 cycles

    30 V, 2 A

    1 × 105 cycles

    Trigger Characteristics

    Input trigger


    PXI trigger lines <0...7>

    Minimum pulse width

    150 ns


    The PXI-2520 can recognize trigger pulse widths less than 150 ns if you disable digital filtering. Refer to the NI Switches Help at for information about disabling digital filtering.

    Output trigger


    PXI trigger lines <0...7>

    Pulse width

    Programmable (1 µs to 62 µs)

    Physical Characteristics

    Relay type

    Electromechanical, non-latching

    Relay contact material

    Palladium-ruthenium, gold covered

    I/O connector

    160 DIN 41612, 160 positions, male

    PXI power requirement

    6 W at 5 V, 2.5 W at 3.3 V

    Dimensions (L × W × H)

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


    174 g (6.1 oz)


    Hardware Diagram

    Figure 2. PXI-2520 Hardware Diagram


    Table 1. NI Accessories for the PXI-2520
    Accessory Part Number
    DIN160 to 50-pin D-SUB switch cable, 1 m 782417-03
    DIN160 to DIN160 switch cable, 1 m 782417-02
    DIN160 to bare wire switch cable, 1 m 782417-01
    Relay replacement kit for Relay replacement kit 782460-10


    Maximum altitude

    2,000 m (at 25 °C ambient temperature)

    Pollution Degree


    Indoor use only.

    Operating Environment

    Ambient temperature range

    0 °C to 55 °C (Tested in accordance with IEC 60068-2-1 and IEC 60068-2-2.)

    Relative humidity range

    10% to 90%, noncondensing (Tested in accordance with IEC 60068-2-56.)

    Storage Environment

    Ambient temperature range

    -40 °C to 71 °C (Tested in accordance with IEC 60068-2-1 and IEC 60068-2-2.)

    Relative humidity range

    5% to 95%, noncondensing (Tested in accordance with IEC 60068-2-56.)

    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, 0.31 grms (Tested in accordance with IEC 60068-2-64.)


    5 Hz to 500 Hz, 2.46 grms (Tested in accordance with IEC 60068-2-64. 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 C22.2 No. 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 electrical equipment for measurement, control, and laboratory use:
    • EN 61326-1 (IEC 61326-1): Class A emissions; Basic immunity
    • EN 55011 (CISPR 11): Group 1, Class A emissions
    • EN 55022 (CISPR 22): Class A emissions
    • EN 55024 (CISPR 24): Immunity
    • AS/NZS CISPR 11: Group 1, Class A emissions
    • AS/NZS CISPR 22: 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, 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

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