TB-2645 and SCB-264x Incompatible - Cannot Access Second Ribbon Cable

Issue Details

I am using the TB-2645 to configure the NI PXI-2532 as either a 2-wire 16x16 matrix or a Dual 1-wire 16x16 matrix. The TB-2645 only has headers to which I can connect ribbon cables. I want to access the individual lines of those ribbon cables by using the SCB-264x Screw Terminal Block. However, I have noticed that the TB-2645 has two 16 pin ribbon cables for the rows, but the SCB-264x has only one 16 pin ribbon connection available, as seen below. Therefore, I can only connect half of my rows at one time. How do I connect the two row ribbon cables of the TB-2645 to the SCB-264x Screw Terminal Block?
 

Solution

The TB-2645 and the SCB-264x are not compatible due to the fact that you will not be able to access the TB-2645's second row ribbon cable when using only one SCB-264x. If you are interested in using the TB-2645 to configure your PXI-2532’s topology, then the following options exist.

• The first option includes using two SCB-264x Terminal Blocks to break out the ribbon cables. One 16-pin row ribbon cable could be connected to each terminal block. The image below illustrates how you would connect your signals to the 16 2-wire rows (in red) and the 16 2-wire columns (in black). The SCB-264x Pin Outs can be seen in the first attachment below.

 

• The next solution involves using one SCB-264x and a custom 16-to-34 pin ribbon cable. This cable has different connectors on either end- a 16 pin connector at one end that can be cabled to the TB-2645’s second row header and a 34 pin connector at the other that can be connected to the SCB-264x’s column headers. Sixteen of the thirty-four pins at that end will access rows 8-15 and the other eighteen pins will have no connection. The signal connection in this case is illustrated below, where the columns are again in black, rows 0-7 are shown in red, and rows 8-15, from the custom cable shown in green. A possible pin out diagram is attached at the bottom of this document.

 

• The third solution available is a custom connection option, such as those available from Virginia Panel Corporation and MAC Panel Company. This option is also discussed in How to Connect Signals to an NI Switch.

Additional Information

The Row and Column Cable Kit for the SCB-264x will only come with one 16 pin ribbon cable. You can either purchase a second cable kit and use its 16 pin ribbon cable for the second SCB-264x, or you can purchase an Matrix Expansion Cable for TB-264xB Terminal Blocks. Though it is called a Column Expansion Cable, this ribbon cable has the necessary 16 pin connector to cable the rows. Be aware it will be 9 inches in length, shorter than the cables in the Row and Column Cable Kit for the SCB-264x (1.5 m cable lengths).

MAC Panel’s SCOUT Product Family is a configurable Mass Interconnect system that provides a PCB or short wire interconnection for your PXI based test system. The MAC Panel's TB-2645 connectivity solution is DAK Assembly number 561149; you can contact the company for more information. MAC Panel purchases the NI front-mounting terminal block and integrates it into the DAK assembly. If you have already purchased the NI terminal block TB-264x, MAC Panel will either a) reduce the price accordingly and let you install the terminal block, or b) let you supply it to MAC Panel to install.