The NI PXI-2568 uses electromechanical armature relays.

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

Relay Manufacturer Part Number
AXICOM (Tyco Electronics) IM42GR (3-1462037-1)
Relay Kit Part Number
National Instruments (10 relays) 779356-01

Complete the following sets of steps to 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.

    Channel Name Relay Name Channel Name Relay Name
    CH0 K1 CH16 K17
    CH1 K2 CH17 K18
    CH2 K3 CH18 K19
    CH3 K4 CH19 K20
    CH4 K5 CH20 K21
    CH5 K6 CH21 K22
    CH6 K7 CH22 K23
    CH7 K8 CH23 K24
    CH8 K9 CH24 K25
    CH9 K10 CH25 K26
    CH10 K11 CH26 K27
    CH11 K12 CH27 K28
    CH12 K13 CH28 K29
    CH13 K14 CH29 K30
    CH14 K15 CH30 K31
    CH15 K16
    Note   Older versions of this module might have plastic lead covers that you must remove. The module retains full specifications even if these covers are not reinstalled.
  3. Locate the assembly and serial number labels on the board with the relay you want to replace. White labels indicate the board was assembled using lead solder (Sn 63 Pb 37). Green labels indicate the board was assembled using lead-free solder (Sn 96.5 Ag 3.0 Cu 0.5). Lead-free assemblies have assembly numbers ending in L.

  4. Replace the relay.
    Note   NI recommends using lead-free solder for relay replacement on lead-free assemblies, and lead solder for relay replacement on lead assemblies.
    Caution   Do not rework lead assemblies using a lead-free work station. Lead solder from the unit could contaminate the station.
    Caution   If a lead-free assembly is reworked with lead solder, label the assembly to indicate this. This can prevent the same unit from being reworked later on a lead-free solder station, which could contaminate the station.

    Make sure you have the following:

    • Temperature-regulated soldering iron set to 316 °C (600 °F) for lead solder rework or 371 °C (700 °F) for lead-free solder rework
    • 63/37 Tin/Lead solder (flux core) for lead solder rework
    • 96.5/3.0/0.5 Tin/Silver/Copper solder (flux core) for lead-free solder rework
    • Solder wick
    • Fine pick
    • Isopropyl alcohol
    • Cotton swabs

    If you have a surface mount rework station, replace the relay as you would any other surface mount part. Otherwise, complete the following steps to replace the relay:

    1. Use the soldering iron and solder wick to remove as much solder from the relay pads as possible. Do not leave the soldering iron on any lead for more than 5 seconds.
      Note   If it is necessary to reapply the soldering iron to the pad, allow the connection to cool completely before reapplying the soldering iron.
    2. Apply heat to the pads one at a time, and use the pick to gently pry the relay pins from the pads. Make sure that the solder is molten before prying.
      Caution   Using excessive force on a soldered pad can result in lifting the PCB trace and ruining the board.
    3. Remove the relay.
    4. Clean the pads with isopropyl alcohol and cotton swabs.
    5. Place the new relay on the PCB pads and solder.
    6. Remove the excess flux with isopropyl alcohol and cotton swabs.
      Caution   Do not use flux remover to clean the board after relay replacement.
Tip   In NI-SWITCH 3.1 or later, you can use the Switch Soft Front Panel to reset the relay count after you have replaced a failed relay. Refer to the Switch Soft Front Panel Help for more information.