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

Updated Jul 28, 2023

Reported In


  • PXIe-2532
  • PXI-2532
  • TB-2645
  • SCB-264X

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?


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.

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.