sbRIO Daughter Board Reference Design for Multisim & Ultiboard

Each NI Single-Board RIO integrates an embedded real-time processor, a high-performance FPGA, and onboard analog and digital I/O onto a single board. All I/O is connected directly to the FPGA, providing low-level customization of timing and I/O signal processing. The FPGA is connected to the embedded real-time processor via a high-speed PCI bus. LabVIEW contains built-in data transfer mechanisms to pass data from the I/O to the FPGA and also from the FPGA to the embedded processor for real-time analysis, post-processing, data logging, or communication to a networked host computer.

Depending upon your application, domain specific signal conditioning may be necessary to effectively complete your design. Such an accessory can also facilitate the interfacing of signals from the Single-Board RIO card to an external source. For example, you may need to breakout a measurement into separate signals to interact with different elements of a system.

Such custom interfaces, or circuitry can be deployed in the form of a daughter card, or expansion card. This additional circuitry provides you as the designer with a compact, yet specific design to acquire and condition electric signals.

The image below (Figure 1) shows an example of the Single-Board RIO. Highlighted in yellow, we see the FPGA onboard the system. Highlighted in red we see the multi-port analog/digital connectors, which are where daughter cards can interface to the embedded platform.

Figure 1 - Single-Board RIO Platform

For this reference design, we are able to use NI suite of circuit prototyping tools: NI Multisim capture and simulation, as well as NI Ultiboard layout and routing. Multisim is an easy-to-use capture environment, which augments the design process with accessible simulation. Ultiboard is a flexible environment to layout PCBs, and export industry standard Gerber files for prototype fabrication.

As NI tools, we are able to provide additional references and materials that will make your design efforts easier, quicker and simpler. Within this reference design you will find a complete set of files including:

1. Multisim file containing a completely captured design
2. Ultiboard file with a completed design, ready for fabrication
3. Connector components and footprints, to be used in your design
4. Gerber files to fabricate your own physical copy of this design

This reference design outlines the methodology to create your own daughter card for the sbRIO-9601/9602 platform. (Figure 2).

Figure 2 - Completed Daughter Card Design for Single-Board RIO

Note

Although this design reference library is intended to be as accurate as possible and has been checked by Application Engineers at NI, it is always recommended to closely check documentation provided with the hardware purchase. It is always suggested that you reference materials associated with NI hardware to verify correct pin assignments and to check correct layout guidelines and pin spacing.

Alongside other design references such as those for breakout boards, C-Series Modules and CompactRIO expansion boards, this design reference contains a library of ready-made schematic symbols, PCB layouts (including board outlines), as well as the database of components for custom design. The purpose of these materials is to aid engineers in being able to leverage the quick and flexible nature of NI design tools (Multisim, Ultiboard, sbRIO) to easily prototype their own platforms.

Download the attached for your content: 8213_design_files.zip.

This zip folder contains:

1. Multisim Design File: sbRIO-960X daughter card reference design.ms10
2. Ultiboard Design File: sbRIO-960X daughter card reference design.ewprj
3. Multisim Database of Connectors: sbRIO_Connectors.prz
4. Ultiboard Database of Connectors: UsrComp_S_SB-RIO.usr
5. Read Me.doc(x): Downloadable instructions on using the above content

As with most design tools, as you embark upon creating a custom design you require symbols and landpatterns for the components that will define your design. Components are the building block of any prototype, and engineers will often spend hours ensuring that the pin mapping, and land pattern definitions are accurate to ensure design effectiveness.

As a part of this reference design a database expansion for NI Multisim and NI Ultiboard is provided, with accurate (and design verified) symbols and landpatterns which will interface to the connectors on the Single-Board RIO platform.

Adding to your Database

The components for Single-Board RIO custom design is provided in the sbRIO_Connectors.prz and UsrComp_S_SB-RIO.usr files. To add the components to your work environment:

1. Download the sbRIO_Connectors.prz file.
2. Extract the contents of the file.
3. Open Multisim (Start > All Programs > National Instruments > Circuit Design Suite 10.1 > Multisim 10.1)
4. Select Tools > Database > Database Manager to open the Database Manager
5. Select the Family tab
6. Select User Database in the Family Tree dialog
7. Expand the User Database by clicking on the + symbol
8. Select the Basic group
9. Click the Add Family button
10. Enter the name NI_Connectors and click on the OK button
11. Select the Components tab
12. Select the User Database
13. Click the Import button
14. Browse to the sbRIO_Connectors.prz file
15. Click on the Open button
16. Select the User Database as your Target Database
17. Click on the Start button
18. Select the default option (Auto-Rename) and click on the OK button
19. Once completed, click on the Close button. You have imported 11 new SB-RIO specific connectors into your Multisim database. It is now time to import into Ultiboard.
20. In Multisim select Tools > Database > Merge Database
21. Click on the Select a Component Database Name button
22. Browse to the UsrComp_S_SB-RIO.usr file
23. Click on Open
24. Click on the Start button
25. Once the merge is completed, click on the Close button.

The mating connectors in the Multisim database (also known as P2, P3, P4 and P5) constitute the connectors that you will need to design for, in order to interface to the low level digital input/output (I/0) on the Single-Board RIO. These connectors are found on a variety of current sbRIO-96XX families.

Depending on the engineer, and the schematic that is being designed, a number of different forms of these connectors have been made available to make design flexible.

Port Connector Symbols

Each connector (P2, P3, P4 and P5) on a design consists of various ports. By symbolically breaking the connector into separate ports, you are able to better handle the design on a schematic, thereby wiring up the circuitry to the mating connector in a far more modular fashion.

The following connectors (Figure 3) show how the P2 is broken out into 4 subsections – Port 5, Port 6, Port 2 (partially shown, as it is shared with a connector section) and Power.

Figure 3 - Port Based Breakdown of Single-Board RIO Connector

Connector Symbol

The symbol below (Figure 4) shows the connector in its entirety by having all ports joined as one. This style allows you to visualize all of the individual pin connections on the appropriate mating connector (in a similar fashion as when you physically prototype a design).  Note that on this style of connector you will have multiple connections to ground and VCC.  

Figure 4 - Single-Board RIO Connector

Connections to individual Port/Line combinations are designated by PX.DY, where X = Port Number and Y = Line Number as specified in the sbRIO user manual documentation.

Landpattern | Mating Connector 50 pin IDC Header

Each of the above symbols (whether chosen to be as a single connector symbol or as multiple ports) map to a landpattern (or footprint) which represents the actual physical dimensions of a real connector on a PCB. The following (Figure 5) shows you the PCB landpattern and the 3D representation of the PCB mating connector for these pins. 

This connector must be oriented on the bottom side of your custom board as it will connect your custom daughter card designs to the Single-Board RIO platform. The connector is called a Conn_50pin_IDC_Female_Vert in the NI Ultiboard database.

• • Conn_50pin_IDC_Female_Vert
  • Details: 50 pin IDC receptacle. (Used on custom sbRIO daughter cards for DIO headers)
  • Manufacturer: 3M 8550-4500

Figure 5 - Mating Connector Landpattern and 3D View

If you wish to learn more about the connectors, example files and templates available for Single-Board RIO design, please consult the Custom Daughter Card Design for NI Single-Board RIO with NI Multisim and Ultiboard article. With this content, you will be able to gain access to all of the various files that have been created, which are your starting point to daughter card design for this platform.

The remainder of this article will provide you with the files needed for a completed daughter card design.

Throughout this document we have spoken about component databases, schematic templates and PCB layouts. All of these are fundamental starting points for your design needs.

In this section of the reference design we however can focus on completed designs, which are ready to be immediately fabricated. With a few changes, or alterations, you can even take these reference designs and make them appropriate for your own custom designs.

With the following reference design, contained in the following file: 8213_design_files.zip, you will find:

1. sbRIO-960X daughter card reference design.ms10 (design schematic)
2. sbRIO-960X daughter card reference design.ewprj (design layout)
3. sbRIO-960X daughter card reference design gerbers.zip (Gerber file output for fabrication)

Reference Design Functionality

This design is a simple counter, which uses the FPGA and Real-Time Processor onboard the Single-Board RIO to light a pattern across a bank of 8 LEDs. 

This is a simple, yet functional design that can help you to leverage the Single-Board RIO’s compact and effective design on a custom daughter card.

Reference Design Schematic

The reference design has been broken into various multi-page schematics that allow us to access to various ports effectively. We have utilized the “port” based breakdown of the connector symbols in this reference design.

To open the schematic:

1. Open Multisim (Start > All Programs > National Instruments > Circuit Design Suite 10.1 > Multisim 10.1)
2. Select File > Open
3. Browse to the sbRIO-960X daughter card reference design.ms10 file. Click on the Open button.
4. You will see the design ready to view in the Design Toolbox (Figure 6).

Figure 6 - Multisim Design Toolbox

5. On the sbRIO-960X daughter card reference design#General page (Figure 7), you can see the introduction schematic for Single-Board RIO designs. This schematic shows a color coded view to each port on the analog/digital connectors.

Figure 7 - Multisim Schematic Guide

6. On the sbRIO-960X daughter card reference design#DigitalOut page (Figure 8), you can see the circuitry that interfaces from the digital output ports to the daughter card (namely the LEDs).

Figure 8 - HCT595 LED Counter Circuit

7. On the sbRIO-960X daughter card reference design#DigitalIn page (Figure 9), you can see the circuitry that interfaces to the digital input ports from the daughter card.

Figure 9 - Digital Input Ports

8. On the sbRIO-960X daughter card reference design#Unused page (Figure 10), you can see the unused ports from this digital design.

Figure 10 - Unused Analog Ports

These simple schematics define the complete reference design. With a complete design, we simply need to take a look at our completed PCB layout.

Reference Design Layout

As mentioned previously the schematic is but one half of a complete design. There is also the layout for us to consider.

To open the layout file:

1. Open Multisim (Start > All Programs > National Instruments > Circuit Design Suite 10.1 > Ultiboard 10.1)
2. Select File > Open
3. Browse to the sbRIO-960X daughter card reference design.ewprj file.

This relatively simple design (Figure 11) has already routed the various signals from the digital I/O mating connectors on the SB-RIO 960x board to the LEDs. There are also appropriate connections to the screw terminals on the outside edge of the board.

Figure 11 - Ultiboard Layout

To view the 3D properties of the board, we can use the 3D view in NI Ultiboard: Select Tools > View 3D.

The 3D representation of the board appears (Figure 12 and 13), and you can use your mouse to rotate the board 360 degrees in all directions. By using the rotation feature, you can see both the top side of the board with the LEDs and screw terminals, as well as the bottom side with the various connectors to mate with the Single-Board RIO design.

Figure 12 - Daughter Card Top View (3D)

Figure 13 - Daughter Card Bottom View (3D)

Reference Design Fabrication Files

For the design all of the various Gerber files that are needed have been generated, allowing you to very easily send your information to the board fabrication house for prototyping. These files are in the Gerber RS-274x standard (the industry standard), and provide PCB manufacturers with a layer-by-layer guide to the design and manufacture of your PCB.

We are now ready to begin exporting our completed file to our fabrication house, in this case Sunstone Circuits. We need to very simply:

1. Select File > Export.
2. The Export dialog box will appear.
3. You have the ability to export to both industry standard formats (Gerber RS-274D and Gerber RS-274X). In this demonstration we will go for the preferred format for Sunstone and most fabrication houses – Gerber RS-274X.
4. Select Gerber RS-274X in the dialog box (figure 14).
5. Click on the Properties button

Figure 14 - Export Dialog Box

6. You will now see the various layers and that can be exported to Gerber from the design (Figure 15).
7. To select multiple layers at once, hold down the CTRL key on the keyboard while clicking the various layer names in the dialog box.

Figure 15 - Gerber File Export

8. Select Board Outlines, Copper Bottom, Copper Inner 1, Copper Inner 2, Copper Top, Silkscreen Top, Silkscreen Bottom, Solder Mask Bottom, Solder Mask Top, and Drill.
9. Click on the > arrow to the right of the “Available Layers” dialog.
10. Click on the OK button.
11. When you return to the Export dialog box you are ready to finally export your files.
12. Click on the Export button.
13. You will now iterate through the various layers of your board that you had previously selected to be exported into the Gerber format.
14. Click on the OK button.
15. Save the file to the appropriate location.
16. Repeat the above process for all of the layers in your design.
17. You are now ready to export the NC Drill file. Again select File > Export.
18. Select NC Drill in the Export dialog box.
19. Click on the Export button. Save the file to the appropriate location.

For NI prototyping, Sunstone Circuits is a member of the Circuit Design Ecosystem. By sending Sunstone Circuits the above Gerber files to their online quick-turn service, you can be guaranteed your finished prototype in as little as a few days. Through our partnership, we have order integration, meaning that Sunstone has a previous knowledge of our circuit files and technology, making the prototype stages simpler.

Navigate to this click to receive a quote on your design and have Sunstone fabricate your prototype.

To learn more about Sunstone Circuits view our 3rd Party Design Network page here.

Figure 16 - 3rd Party Design Network

With Multisim, Ultiboard and the various resources available on ni.com, you have the tools to architect custom designs such as daughter cards, C-Series modules, accessories and connectors to complete your NI design platforms.

To learn more about board-level design with Multisim and Ultiboard:

• Download a 30 Day Free Evaluation of Multisim and Ultiboard
• Learn more at ni.com/multisim