How to Connect Signals to the SCXI-1130

Overview

The National Instruments SCXI-1130 is a high-density, multiconfiguration multiplexer/matrix switch module. With four multiplexer and three matrix configurations, the NI SCXI-1130 is an excellent solution for large or complex-channel-count systems. Multiplexer configurations include 256x1 (1-wire), 128x1 (2-wire), 64x1 (4-wire), or 16 banks of 16x1 (1-wire). Matrix configurations include 4x64 (1-wire), 8x32 (1-wire), or 4x32 (2-wire). These configurations are made available through the selection of an appropriate terminal block. With the speed of reed relays, the SCXI-1130 is an ideal front-end for high-speed measurement devices, such as the NI PXI-4070 6½-digit FlexDMM.

SCXI-1130 Terminal Blocks

There are three terminal blocks available for the SCXI-1130:

· SCXI-1377: 256x1 1 –wire, 128x1 2 –wire, 64x1 4 –wire multiplexer
· SCXI-1378: 4x64 1 –wire, 4x32 2 –wire matrix
· SCXI-1379: 8x32 1 –wire matrix

SCXI-1377

The National Instruments SCXI-1377 configures the SCXI-1130 as a multiplexer with several optional sizes. It creates 256x1 (1-wire), 128x1 (2-wire), and 64x1 (4-wire) configurations instantly. The NI SCXI-1377 will also accomodate other multiplexer sizes based on the 16x1 building blocks of the SCXI-1130. Connections are made with spring terminals inside the housing.

The figure below outlines the main components of the SCXI-1377:

The figure below outlines how the spring terminals on the SCXI-1377 map to the channels on the SCXI-1130:
A larger image can be found in the NI SCXI-1377 Installation Instructions, on page 5.

The Signal Connection with Terminal Blocks section below will outline how the SCXI-1377 terminals map to a particular topology of the SCXI-1130.

SCXI-1378

The National Instruments SCXI-1378 configures the NI SCXI-1130 high-density matrix switch as a 4x64 (1-wire) or 4x32 (2-wire) matrix. It provides direct signal wire connection to the screw terminals inside the terminal block. The terminal block works with the use of NI matrix expansion plugs for instant row expansion via column connection, requiring no external wiring.

The figure below outlines the main components of the SCXI-1378:


The figure below clearly outlines how the screw terminals on the SCXI-1378 map to the rows and columns of the SCXI-1130:
A larger image can be found in the NI SCXI-1378 Installation Instructions, on page 5.

The Signal Connection with Terminal Blocks section below will outline how the SCXI-1378 terminals map to a particular topology of the SCXI-1130.

SCXI-1379
The National Instruments SCXI-1379 configures the NI SCXI-1130 high-density matrix switch as an 8x32 (1-wire) matrix. It provides direct signal wire connection to screw terminals inside the terminal block. The terminal block works with NI matrix expansion plugs for instant row expansion via column connection, requiring no external wiring.



The figure below clearly outlines how the screw terminals on the SCXI-1379 map to the rows and columns of the SCXI-1130:


A larger image can be found in the NI SCXI-1379 Installation Instructions, on page 5.The Signal Connection with Terminal Blocks section below will outline how the SCXI-1379 terminals map to a particular topology of the SCXI-1130.

Signal Connection with Terminal Blocks

The SCXI-1130 is capable of 1-wire, 2-wire and 4-wire multiplexer toplogies as well as 3 different matrix topologies. The SCXI-1377, SCXI-1378 and SCXI-1379 terminal blocks, in conjunction with the software, determine which of these topologies is implemented and how the signals should be connected.

SCXI-1377

The SCXI-1377 will be used for multiplexer topology applications of the SCXI-1130.

Below is an actual image of the SCXI-1377 outlining the various connections:




To connect signals to the SCXI-1130 via the SCXI-1377, prepare the signal wire by stripping the insulation no more than 7mm. Run the signal wires through the strain-relief opening and then attach them to the required terminals by pressing the corresponding spring pad with a flathead screw driver and inserting the stripped end fully into the terminal. Release the spring pad to secure the wire. No exposed wire should extend past the spring terminal. Ensure that the signal wires are properly reinforced by the strain relief bar, and then attach the terminal block cover. The terminal block can then be connected directly to the switch via the mating connectors as shown in the following figure:



Mapping of spring terminals on the SCXI-1377 to the channels of the SCXI-1130 for a particular multiplexer topology are available on the tables in pages 6 through 10 of the NI SCXI-1377 Installation Instructions.

Table 1 outlines the 256x1, 1-Wire Multiplexer Topology mapping. This table also applies to all other 1-Wire Multiplexer Topologies for the SCXI-1130 such as Dual 128x1, Quad 64x1etc.

Table 2 outlines the 128x1, 2-Wire Multiplexer Topology mapping. This table also applies to all other 2-Wire Multiplexer Topologies for the SCXI-1130 such as Quad 32x1 and Octal 16x1.

Table 3 outlines the 64x1, 4-Wire Multiplexer Topology mapping. This table also applies to the 4-wire Quad 16x1 Multiplexer Topology.

For specfic information on the mapping of the different banks in Dual, Quad, Octal and Sixteen topologies open up NI Switches Help and navigate as follows:
NI Switches Help > Devices > NI SCXI-1130 and select the corresponding topology. For example, for 2-Wire Quad 32x1 Multiplexer Topology using the SCXI-1377 with the SCXI-1130 we have:



SCXI-1378

The SCXI-1378 will be used for 4x64 1-wire and 4x32 2-wire matrix applications of the SCXI-1130.

Below is an actual image of the SCXI-1378 outlining the various connections:

The screw terminals are clearly labeled on the SCXI-1378. To determine how they correspond to the matrix rows and columns of the SCXI-1130 navigate to: NI-Switches Help > Devices > NI SCXI-1130 > Signal Connections and then select either 1-Wire 4x64 Matrix Topology or 2-Wire 4x32 Matrix Topology.

To connect signals to the SCXI-1130 via the SCXI-1378, screw the leads into the screw terminals as required, ensure that the leads are properly reinforced by the strain relief bar and then attach the terminal block cover. The terminal block can then be connected directly to the switch via the mating connectors as shown in the following figure:


SCXI-1379

The SCXI-1379 will be used for 8x32 1-Wire matrix applications of the SCXI-1130.

Below is an actual image of the SCXI-1379 outlining the various connections:

The screw terminals are clearly labeled on the SCXI-1379. To determine how they correspond to the matrix rows and columns of the SCXI-1130 navigate to: NI-Switches Help > Devices > NI SCXI-1130 > Signal Connections > 1-Wire 8x64 Matrix Topology.

To connect signals to the SCXI-1130 via the SCXI-1379, screw the leads into the screw terminals as required, ensure that the leads are properly reinforced by the strain relief bar and then attach the terminal block cover. The terminal block can then be connected directly to the switch via the mating connectors as shown in the following figure:
Matrices of the NI SCXI-1130 can be expanded in two ways: by expanding rows and expanding columns.

Row expansion for the SCXI-1130 involves using the Matrix Expansion Plug, which connects the columns between matrices to expand the number of rows. When used with the SCXI-1378 this will allow for 8x64, 12x64 etc. 1-wire matrix topologies and 8x32, 12x32 etc. 2-wire matrix topologies. When used with the SCXI-1379 this will allow for 16x32, 24x32 etc. 2-wire matrix topologies. The Matrix Expansion Plugs can be connected either on the top or botton of adjacent terminal blocks for SCXI-1130 modules. The following figure illustrates the concept of using two SCXI-1378/SCXI-1130s together in order expand the overall matrix to become 8x32 2-wire:
Column exapnsion for the SCXI-1130 involves using the Matrix Expansion Cable, which connects the rows between matrices to expand the number of columns. When used with the SCXI-1378 this will allow for 4x128,4x192 etc. 1-wire matrix topologies and 4x64, 4x96 etc. 2-wire matrix topologies. When used with the SCXI-1379 this will allow for 8x64, 8x96 etc. 2-wire matrix topologies. The Matrix Expansion Cable should be connected from one terminal blocks' Row Connection Cable Terminal to another Row Connection Cable Terminal. The following figure illustrates the concept of using two SCXI-1378/SCXI-1130s together in order to exapnd the overall matrix to be come 4x64 2-wire:

Custom Termination Options for the SCXI-1130

The SCXI-1130 can be utilized without the SCXI-1377, SCXI-1378 or SCXI-1379.

By using two mating front panel connectors, users can develop their own terminal block. A custom terminal block can connect and arrange any of the rows and columns of the 16 banks of the SCXI-1130 as required.Navigate from the NI Switches Help to Devices > NI SCXI-1130 > Signal Connections and select the desired topology to view pin-outs fro each toplogy.

Vendors of mating front panel connectors can be seen in the following table:

Accessory	Manufacturer	Manufacturer Part Number
Mating front panel connector, right-angle	Molex	52755-1760

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