Migration Paths for Analog Vision Systems


Industrial digital cameras are the popular choice for machine vision, scientific imaging, and automated test systems. If you already have an analog camera system, NI makes it easy to migrate to digital. If you prefer analog cameras, NI offers several options below to help with your applications. 

Figure 1. This diagram illustrates both migration paths, with all changing system components represented in green.

Migrating to Digital Cameras

Benefits of Digital

Digital camera technologies and standards offer equivalent and superior camera options compared to analog cameras. In general, with digital standards, you can

  • Use sensors with higher resolution, frame rates, and pixel depth
  • Perform partial image sensor readouts
  • Configure camera attributes more easily
  • Synchronize and integrate inspections with lower latency
  • Interconnect cameras through hubs

Choosing a Digital Standard

You can choose from a variety of digital standards. Table 1 compares the digital options to analog.

Table 1. Comparison of Analog with Digital Technologies

How the Change Affects Application Software

When moving from analog to digital cameras, consider how the following two options may affect your application software code:

  • Option A: Camera Link, which also uses NI-IMAQ image acquisition drivers, so it requires minimal changes, if any, to code.
  • Option B: Consumer buses that use NI-IMAQdx, which is a separate driver, but, as you can see from the diagrams below, it features a one-to-one correlation with NI-IMAQ driver functions.

Figure 2. The One-to-One Correlation between the NI-IMAQ and NI-IMAQdx Drivers as Seen through the Similarities in the LabVIEW Function Palettes


Figure 3. This LabVIEW VI is performing image acquisition and thresholding using (a) NI-IMAQ and (b) NI-IMAQdx.


Using Analog Cameras

If you need to continue using your analog camera, you can choose from the following options including third-party products. 

  • Option A: Analog Capture Card
    Many companies provide analog capture cards that capture analog video and broadcast it using DirectShow over many different bus interfaces, including USB, IEEE 1394, Ethernet, and PCI. Models that use DirectShow should be detectable by the NI-IMAQdx image acquisition driver. Capture cards are consumer-grade electronics and are readily available, both online and in local electronics stores. You also can use signal converters that convert analog signals to Ethernet.  
  • Option B: Third-Party Frame Grabbers
    Several companies provide analog frame grabbers with drivers that you can interface to LabVIEW through DLL calls.

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