PXI-2565 Overview

PXI-2565 Pinout


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Table 1. Signal Descriptions
Signal Description
CHx Signal connection
COMx Routing destination for the corresponding channel

PXI-2565 Hardware Diagram

This figure shows the hardware diagram of the module.


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PXI-2565 Topology

Module software name: 2565/16-SPST (NISWITCH_TOPOLOGY_2565_16_SPST)

The module is composed of 16 SPST relays.

Note 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.

16-SPST Topology


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Making a Connection

You can control the channels using the niSwitch Connect Channels VI or the niSwitch_Connect function.

For example, to close the relay of channel 2, call niSwitch_Connect(vi, "ch2", "com2"). To open the relay of channel 2, call niSwitch_Disconnect(vi, "ch2", "com2").

When scanning the module, a typical scan list entry could be ch2->com2;. This entry routes the signal connected to CH2 to COM2.

PXI-2565 Flyback Voltage Protection

When inductive loads are connected to the relays, a large counter electromotive force may occur at relay switching time because of the energy stored in the inductive load. These flyback voltages can severely damage the relay contacts and significantly shorten the life of the relay.

You can limit flyback voltages at your inductive load by installing a flyback diode for DC loads or a varistor for AC loads. The module has solder connections for a diode or varistor. With this diode/varistor installed, you can limit flyback voltages when switching inductive loads.

Notice Before installing the diode or varistor in your module, ensure that no signals are connected to your module front connector.

Before installing your switch module in the PXI chassis, install the diode/varistor by performing the steps described in the following sections.

Disassemble the Module

To disassemble the module, complete the following steps, referring to the parts locator diagram as needed.

  1. Ground yourself using a grounding strap or a ground connected to your PXI chassis.
    Note Properly grounding yourself prevents damage to your module from electrostatic discharge.
  2. Loosen the four screws that fasten the relay module to the carrier module and front panel.

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    1. Carrier Module
    2. Solder Location for Flyback Voltage Protection Device
    3. Relay Module
    4. Screws
    5. Plastic Insulator Cover
    6. Relay and Socket
    7. Ribbon Cable
  3. Remove the plastic insulator cover.
  4. Lift up the card and disconnect the ribbon cable from the relay module.

Install the Diode/Varistor

Complete the following steps to install the diode/varistor.

  1. Remove solder, as necessary, from the diode/varistor locations.
  2. Insert the diode/varistor into the appropriate location, labeled RVx, where x corresponds to the channel number.
  3. Solder and trim the leads.
  4. Reassemble the module by completing the Disassemble the Module steps in reverse order.

PXI-2565 Relay Replacement

The module uses socketed electromechanical relays.

Refer to the following table for information about ordering replacement relays.

Replacement Relay Part Number
Aromat (NAiS) (relay manufacturer) DSP1a-DC5V
NI relay kit (16 relays) 777880-01

Complete the following steps to disassemble your module and replace a failed relay.

  1. Ground yourself using a grounding strap or a ground connected to your PXI chassis.
    Note Properly grounding yourself prevents damage to your module from electrostatic discharge.
  2. Locate the relay you want to replace. Refer to the following figure and table for relay locations.
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    Channel NameRelay NameChannel NameRelay NameChannel NameRelay NameChannel NameRelay Name
    CH0 K0 CH4K4CH8K8CH12K12
    CH1K1CH5K5CH9K9CH13K13
    CH2K2CH6K6ch10K10CH14K14
    CH3K3CH7K7CH11K11CH15K15
  3. Remove the four screws that fasten the daughtercard to the main board.
  4. Lift up the card as shown in the following figure.
    Figure 1. Disassembling the Module

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    1. Carrier Module
    2. Solder Location for Flyback Voltage Protection Device
    3. Relay Module
    4. Screws
    5. Insulator
    6. Relay and Socket
    7. Ribbon Cable
  5. Remove the relay by gently applying force.
  6. Before inserting the new relay, match the direction of the relay and the socket.
  7. Insert the relay, making sure the relay is properly seated and the socket hooks the top of the relay.