PXI-2568 Pinout

15-DPST Topology



Table 1. Signal Descriptions
Signal Description
CHxW0 Wire 0 signal connection
CHxW1 Wire 1 signal connection
COMxW0 Routing destination for W0 on the corresponding channel
COMxW1 Routing destination for W1 on the corresponding channel
— No connection

31-SPST Topology



Table 2. Signal Descriptions
Signal Description
CHx Signal connection
COMx Routing destination for the corresponding channel

PXI-2568 Hardware Diagram

This figure shows the hardware diagram of the module.



Topologies

PXI-2568 15-DPST Topology

Module software name: 2568/15-DPST (NISWITCH_TOPOLOGY_2568_15_DPST)

The module is composed of 31 armature latching SPST relays.

For certain applications, you may need to increase the default settling time.

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.

15-DPST Topology



Making a Connection

Both the scanning command, ch2->com2;, and the immediate operation, niSwitch Connect Channels VI or the niSwitch_Connect function with parameters ch2 and com2, result in the following connections:

  • signal connected to CH2W0 is routed to COM2W0
  • signal connected to CH2W1 is routed to COM2W1

PXI-2568 31-SPST Topology

Module software name: 2568/31-SPST (NISWITCH_TOPOLOGY_2568_31_SPST)

The module is composed of 31 armature latching SPST relays.

For certain applications, you may need to increase the default settling time.

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.

31-SPST Topology



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 closes the relay between CH2 and COM2.

PXI-2568 Relay Replacement

The module uses electromechanical armature relays.

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

Replacement Relay Part Number
AXICOM (Tyco Electronics) (relay manufacturer) IM42GR (3-1462037-1)
NI relay kit (10 relays) 779356-01

Ensure you have the following:

  • Temperature-regulated soldering iron
    • Set to 371 °C (700 °F) for lead-free solder rework
    • Set to 316 °C (600 °F) for lead solder rework
  • Solder
    • 96.5/3.0/0.5 Tin/Silver/Copper solder (flux core) for lead-free solder rework
    • 63/37 Tin/Lead solder (flux core) for lead solder rework
  • Solder wick
  • Fine pick
  • Isopropyl alcohol
  • Cotton swabs
Note NI recommends using lead-free solder for relay replacement on lead-free assemblies, and lead solder for relay replacement on lead assemblies.
Notice Do not rework lead assemblies using a lead-free work station. Lead solder from the unit could contaminate the station.
Notice 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.

Complete the following sets of 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.

    Channel NameRelay NameChannel NameRelay Name
    CH0 K1CH16K17
    CH1K2CH17K18
    CH2K3CH18K19
    CH3K4CH19K20
    CH4K5CH20K21
    CH5K6CH21K22
    CH6K7CH22K23
    CH7K8CH23K24
    CH8K9CH24K25
    CH9K10CH25K26
    ch10K11CH26K27
    CH11K12CH27K28
    CH12K13CH28K29
    CH13K14CH29K30
    CH14K15CH30K31
    CH15K16——
    Note Older versions of this module might have adhesive plastic lead covers that you must remove. The module retains full specifications even if the covers are not reinstalled.
  3. Locate the assembly and serial number labels on the board with the relay you want to replace.
    • Green labels indicate the board was assembled using lead-free solder (Sn 96.5Ag 3.0Cu 0.5). Lead-free assemblies have assembly numbers ending in L.
    • White labels indicate the board was assembled using lead solder (Sn 63Pb 37).
    The different label types are shown in the following figure.

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.
    Notice 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.
    Notice Do not use flux remover to clean the board after relay replacement.
Tip Use the NI-SWITCH 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.