PXI-2527 Specifications

Definitions

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 performance met by a majority of models.
  • Nominal specifications describe an attribute that is based on design, conformance testing, or supplemental testing.
Specifications are Typical unless otherwise noted.

Conditions

Specifications are valid at 23 °C unless otherwise noted.

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

PXI-2527 Pinout

The following figure shows the terminals on the PXI-2527 connector.

Figure 1. PXI-2527 Pinout


1-Wire 64x1 Multiplexer Signal Descriptions

Signal Description
CHx Channel terminals
COM0+ Routing destination for all channel terminals
COM0- Routing destination for the 1WREF0 lead
Note   In the 1-wire 64×1 multiplexer topology, do not connect to A18 or B18, as they are internally connected to certain routes.

1-Wire Dual 32×1 Multiplexer Signal Descriptions

Signal Description
CH0 through CH31 Channel terminals that route to COM0+
CH 32 through CH63 Channel terminals that route to COM1+
COM0+ Routing destination for CH0 through CH31
COM1+ Routing destination for CH32 through CH63
COM0- Routing destination for the 1WREF0 lead
COM1- Routing destination for the 1WREF1 lead

2-Wire 32×1 Multiplexer Signal Descriptions

Signal Description
CH0+ through CH31+ Channel terminals that route to COM0+
CH0- through CH31- Channel terminals that route to COM0-
COM0+ Routing destination for all positive channels
COM0- Routing destination for all negative channels
Note   In the 2-wire 32×1 multiplexer topology, do not connect to A18 or B18, as they are internally connected to certain routes.

2-Wire Dual 16×1 Multiplexer Signal Descriptions

Signal Description
CH0+ through CH15+ Channel terminals that route to COM0+
CH0- through CH15- Channel terminals that route to COM0-
CH16+ through CH31+ Channel terminals that route to COM1+
CH16- through CH31- Channel terminals that route to COM1-
COM0+ Routing destination for CH0+ through CH15+
COM0- Routing destination for CH0- through CH15-
COM1+ Routing destination for CH16+ through CH31+
COM1- Routing destination for CH16- through CH31-

4-Wire 16×1 Multiplexer Signal Descriptions

Signal Description
CH0A+ through CH15A+ Channel terminals that route to COM0+
CH0A- through CH15A- Channel terminals that route to COM0-
CH0B+ through CH15B+ Channel terminals that route to COM1+
CH0B- through CH15B- Channel terminals that route to COM1-
COM0+ Routing destination for all positive channels (A and B)
COM0- Routing destination for all negative channels (A and B)
Table 1. Independent Topology Signal Descriptions
Signal Description
CHx Channel terminals
COM0+ Routing destination for all channel terminals
COM0- Routing destination for the 1WREF0 lead

Topology

Topologies

1-wire 64 × 1 multiplexer

1-wire dual 32 × 1 multiplexer

2-wire 32 × 1 multiplexer

2-wire dual 16 × 1 multiplexer

4-wire 16 × 1 multiplexer

Independent

Input Characteristics

All input specifications are DC, ACrms, or a combination unless otherwise specified.

Caution This module is rated for Measurement Category I and is intended to carry signal voltages no greater than 300 V. This module can withstand up to 1,500 V impulse voltage. Do not use this module for connections to signals or for measurements within Measurement Categories II, III, or IV.
Attention Ce module est conçu pour la catégorie de mesure I et pour supporter des tensions de signal ne dépassant pas 300 V. Ce module peut supporter une tension d'impulsion allant jusqu'à 1500 V. N'utilisez pas ce module pour le connecter à des signaux ou effectuer des mesures de catégorie de mesure CAT II, III ou IV.
Caution Do not connect to MAINs supply circuits (e.g., wall outlets) of 115 or 230 VAC. Refer to the Read Me First: Safety and Electromagnetic Compatibility document for more information about Measurement Categories.
Attention Ne connectez pas ce module au réseau d'alimentation électrique du secteur (prises murales, par exemple) de 115 VCA ou 230 VCA. Reportez-vous au document Read Me First: Safety and Electromagnetic Compatibility pour en savoir plus sur les catégories de mesure.
Caution When hazardous voltages (>42.4 Vpk/60 VDC) are present on any relay terminal, safety low-voltage (≤42.4 Vpk/60 VDC) cannot be connected to any other relay terminal.
Attention Lorsque des tensions dangereuses (> 42,4 Vpic/60 VCC) sont présentes sur une borne de relais, la basse tension de sécurité (≤42,4 Vpic/60 VCC) ne peut être connectée à aucune autre borne de relais.
Maximum switching voltage[1]1 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 ni.com/info and enter the Info Code induct.

Channel-to-channel

300 V

Channel-to-ground

300 V, CAT I

Caution The maximum switching power is limited by the maximum switching current, the maximum voltage, and must not exceed 60 W, 62.5 VA.
Maximum switching power (per channel)

AC systems

60 W, 62.5 VA (up to 60 Hz)

DC systems

Refer to the following figure.

Figure 2. Maximum Switching Power for DC Loads (per channel)


Maximum total current (switching or carry)

2 A

Minimum switch load[2]2 The minimum switch load is not recommended for 2-wire resistance measurements.

20 mV /1 mA

DC path resistance[3]3 DC path resistance typically remains low for the life of the relay. At the end of relay life, the path resistance rapidly rises above 1 Ω. Load ratings apply to relays used within the specification before the end of relay life.

Initial

<1 Ω, warranted

End-of-life

≥2 Ω

Differential thermal EMF

2.5 μV, typical[4]4 To ensure the typical thermal EMF, power down all relays and avoid pulsing high currents near the channels you are measuring. For more information about powering down latching relays, refer to the Power Down Latching Relays After Debounce property in NI-SWITCH or the Power Down Latching Relays After Settling property in NI-DAQmx.

<12 μV, maximum

Channel-to-channel DC leakage at 300 V

500 GΩ

Bandwidth (-3 dB, 50 Ω termination)

1-wire

>30 MHz

2-wire

>25 MHz

Channel-to-channel isolation (50 Ω termination) (1-wire and 2-wire)

10 kHz

>80 dB

100 kHz

>60 dB

1 MHz

>40 dB

Open channel isolation (50 Ω termination) (1-wire and 2-wire)

10 kHz

>80 dB

100 kHz

>60 dB

1 MHz

>40 dB

Dynamic Characteristics

Warning Device relays might change state momentarily during electrostatic discharge.

Relay operate time[5]5 Certain applications may require additional time for proper settling. Refer to the NI Switches Help for more information about including additional settling time.

4 ms, maximum

Expected Relay Life

Note The relays used in the PXI-2527 are field replaceable. Refer to the NI Switches Help for information about replacing a failed relay.
Mechanical 1 × 108 cycles
Electrical 300 VDC, 60 mADC resistive 5 × 105 cycles
30 VDC, 2 ADC resistive 1 × 105 cycles
<30 mV, <10 mA 2.5 × 106 cycles

Trigger Characteristics

Table 2. Input Trigger
Sources PXI trigger lines <0...7>
Minimum pulse width 150 ns
Note The PXI-2527 recognizes pulse widths less than 150 ns if digital filtering is disabled. Refer to the NI-SWITCH User Manual for information about disabling digital filtering.
Table 3. Output Trigger
Destinations PXI trigger lines <0...7>
Default pulse width 2 µs, typical

Thermocouple Measurement

You can use the PXI-2527 and the TB-2627 to measure thermocouples. NI software can convert a thermocouple voltage to the thermocouple temperature. For example code, visit ni.com/examples, and enter PXI-2527 in the Search field.

When measuring thermocouples, be sure to account for error in your measurements. The total error in thermocouple measurement is the sum of the system error (determined by the thermal EMF of the PXI-2527 and the CJC temperature of the TB-2627) and the thermocouple error (determined by the type of thermocouple used).

Determining the System Error

To determine the system error for the PXI-2527 and TB-2627, first calculate the error due to thermal EMF of the PXI-2527 using the following equation:

E E M F = ( T + 1   −   T V + 1   −   V ) ( V E M F ⁢ ) E E M F = ( T + 1   −   T V + 1   −   V ) ( V E M F ⁢ )

where[6]6 In thermocouple reference tables, T and T+1 are known values used to calculate the slope of the thermocouple Temperature vs. Voltage graph. Refer to a thermocouple reference table to determine the values of V and V+1 that correspond to T and T+1, respectively.

  • E EMF = error due to thermal EMF of the PXI-2527
  • T = temperature being measured, in degrees Celsius
  • T +1 = T + 1 °C
  • V = voltage that corresponds to T
  • V +1 = voltage that corresponds to T+1
  • V EMF = thermal EMF of the PXI-2527[7]7 Refer to the Input section of this document to determine the thermal EMF value of the PXI-2527. For optimal thermocouple measurement performance (VEMF = 2.5 μV), power down the latching relays of the PXI-2527. For more information about powering down latching relays, refer to the Power Down Latching Relays After Debounce property in NI-SWITCH or the Power Down Latching Relays After Settling property in NI-DAQmx.

After you have determined the error due to thermal EMF, calculate the system error using the following equation.

E S = EEMF + ECJC

where

  • E S = system error of the PXI-2527/TB-2627
  • E EMF = error due to thermal EMF of the PXI-2527
  • E CJC = error due to CJC temperature sensor of the TB-2627[8]8 From 15 °C to 35 °C, the TB-2627 has an accuracy of ±0.5 °C. From 0 °C to 15 °C and 35 °C to 55 °C, the TB-2627 has an accuracy of ±1.0 °C. For more information about temperature sensor accuracy, refer to the TB-2627 Installation Instructions.

Example

Measuring a K-type thermocouple at 200 °C with a CJC temperature of 25 °C, the system error of the PXI-2527/TB-2627 is calculated below.[9]9 In this example, the values of V and V+1 are found in the thermocouple reference tables of Omega Engineering’s The Temperature Handbook. Vol. 29. Stamford, CT: Omega Engineering Inc, 1995.

Assuming typical thermal EMF (2.5 μV), first calculate the error due to thermal EMF using the following equation:

E E M F = ( 201 °C   −   200 °C 8.178 mV   −   8.138 mV ) ( 0.0025 mV ⁢ ) = 0.063 °C E E M F = ( 201 °C   −   200 °C 8.178 mV   −   8.138 mV ) ( 0.0025 mV ⁢ ) = 0.063 °C

To determine the system error, add the error due to thermal EMF to the error due to the CJC temperature sensor using the following equation.

E S = 0.063 °C + 0.5 °C = 0.563 °C

Determining the Thermocouple Error

Independent of the PXI-2527/TB-2627 system, thermocouple error is the greater of the following values: ±temperature range or ±percent of the measurement.

In the example, a standard grade K-type thermocouple is used to measure 200 °C. The error for a standard grade K-type thermocouple is ±2.2 °C or ±0.75% of the measurement temperature.[10]10 Omega Engineering. The Temperature Handbook. Vol. 29. Stamford, CT: Omega Engineering Inc, 1995. Because ±0.75% of 200 °C (±1.5 °C) is less than ±2.2 °C, the error of a standard grade K-type thermocouple is ±2.2 °C.

Determining the Total Error

The total error in thermocouple measurement is the sum of the system error and the thermocouple error. Use the following equation to determine the total error in thermocouple measurement:

E T = ES + ETh

where

  • E T = total error in thermocouple measurement
  • E S = system error
  • E Th = thermocouple error

To determine the total error in thermocouple measurement in the example, add the thermocouple error to the system error using the following equation:

E T = 0.56 °C + 2.2 °C = 2.76 °C

Assuming typical thermal EMF, the total error in thermocouple measurement at 200 °C for the PXI-2527/TB-2627 with a K-type thermocouple is ±2.76 °C.

Physical Characteristics

Relay type

Electromechanical, latching

Relay contact material

Palladium-ruthenium, gold covered

I/O connector

100-position HDI right angle, male

Power requirement

PXI

6 W at 5 V

2.5 W at 3.3 V

PXI Express

7.5 W at 12 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.)

Weight

209 g (7.4 oz)

Environment

Note If you are using the PXI-2527 with the PXI-101x or the PXI-1000 chassis, the operating temperature for the PXI-2527 is 0 °C to 45 °C. Do not operate the PXI-2527 above the maximum operating temperature of the chassis.

Operating temperature

0 °C to 55 °C

Storage temperature

-20 °C to 70 °C

Relative humidity

5% to 85%, noncondensing

Pollution Degree

2

Maximum altitude

2,000 m

Indoor use only.

Shock and Vibration

Table 4. 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, operating 5 Hz to 500 Hz, 0.3 grms
Random vibration, nonoperating 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.)

1 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 ni.com/info and enter the Info Code induct.

2 The minimum switch load is not recommended for 2-wire resistance measurements.

3 DC path resistance typically remains low for the life of the relay. At the end of relay life, the path resistance rapidly rises above 1 Ω. Load ratings apply to relays used within the specification before the end of relay life.

4 To ensure the typical thermal EMF, power down all relays and avoid pulsing high currents near the channels you are measuring. For more information about powering down latching relays, refer to the Power Down Latching Relays After Debounce property in NI-SWITCH or the Power Down Latching Relays After Settling property in NI-DAQmx.

5 Certain applications may require additional time for proper settling. Refer to the NI Switches Help for more information about including additional settling time.

6 In thermocouple reference tables, T and T+1 are known values used to calculate the slope of the thermocouple Temperature vs. Voltage graph. Refer to a thermocouple reference table to determine the values of V and V+1 that correspond to T and T+1, respectively.

7 Refer to the Input section of this document to determine the thermal EMF value of the PXI-2527. For optimal thermocouple measurement performance (VEMF = 2.5 μV), power down the latching relays of the PXI-2527. For more information about powering down latching relays, refer to the Power Down Latching Relays After Debounce property in NI-SWITCH or the Power Down Latching Relays After Settling property in NI-DAQmx.

8 From 15 °C to 35 °C, the TB-2627 has an accuracy of ±0.5 °C. From 0 °C to 15 °C and 35 °C to 55 °C, the TB-2627 has an accuracy of ±1.0 °C. For more information about temperature sensor accuracy, refer to the TB-2627 Installation Instructions.

9 In this example, the values of V and V+1 are found in the thermocouple reference tables of Omega Engineering’s The Temperature Handbook. Vol. 29. Stamford, CT: Omega Engineering Inc, 1995.

10 Omega Engineering. The Temperature Handbook. Vol. 29. Stamford, CT: Omega Engineering Inc, 1995.