1. Why You Need Custom Hardware
You may need a custom fixture to complete your platform, in addition to the modules and accessories available for these products. For example, you may require custom signal conditioning to interface real-world signals to a control system, or to connect signals through a breakout board. Using Multisim 12.0 and NI Ultiboard 12.0, you can prototype custom circuitry and accessories to complete your design.
With NI myDAQ, educators can create custom systems (or minisystems) to reinforce engineering and science concepts. The minisystem is an external accessory board that plugs into NI myDAQ and interfaces with real-world sensors and signals to teach solutions to relevant engineering challenges. For example, with the NI myDAQ power grid minisystem, students can learn the concepts of renewable energy and sustainability through systems that fit in the palms of their hands and cost less than $99 USD. This can be a better solution than components connected through a breadboard and wires.
Figure 1. NI myGrid Minisystem
2. Multisim Connector Database
Multisim includes a database of 118 symbols and land patterns for NI mating connectors. Using these connectors, you can interface a custom PCB designed in Multisim to NI hardware, including NI myDAQ; CompactRIO; NI Single-Board RIO; E Series, M Series, R Series, and X Series DAQ; and SCXI DAQ.
To access these components
- Open Multisim (Start»All Programs»National Instruments»Circuit Design Suite 12.0»NI Multisim 12.0).
- Select Place»Components.
- Select Master Database in the Database dialog.
- Select NI_Components in the Group dialog.
- View the nine separate families of components (Figure 2).
Figure 2. Selecting a Component in Multisim
3. Creating a Custom Design or Minisystem
To build a minisystem with NI myDAQ, use the steps to design and implement a PCB. The following example shows the steps to develop a pulse oximeter minisystem to monitor the heart rate of a person using a light-detecting resistor and an LED.
Defining the Connector
Creating a custom design requires symbols and land patterns for the components defining your design. Components are the building blocks of any prototype, and you can spend hours ensuring that the pin-mapping and land-pattern definitions are correct. An inaccurate symbol can result in hours of prototype rework. Multisim includes a library of connectors for NI hardware accessory design, including NI myDAQ. This library can save hours in your design flow.
Figure 3. Placing the NI myDAQ Connector in Multisim
Building a Schematic
Common, repetitive tasks can be difficult due to numerous design modes and messy wiring. Multisim simplifies schematic capture by making repetitive tasks intuitive. For example, rather than switching to a wiring mode, you can connect symbols automatically.
Figure 4. Designing the Pulse Oximeter Minisystem in Multisim
Transferring to Layout
Using the Ultiboard interface, you can efficiently lay out and route PCB designs. With complete integration into Multisim, you can transfer Multisim schematics to design PCBs. The intuitive, user-friendly layout and routing tools help you quickly prototype your design and export to industry-standard Gerber or DXF formats for fabrication.
Multisim 12.0 includes nearly 120 ready-to-use NI connectors so you can create custom designs, breakout boards, and minisystems with NI hardware, including NI myDAQ. The new components can save you time as you create custom circuitry or minisystems to complete your application designs.