Machine Vision Cameras on GigE: 5 GigE, 10GigE

Gigabit Ethernet is the most widely used interface in industrial image processing due to low system costs, cables up to 100 m in length and the GigE Vision standard for easy integration. The ongoing trend toward higher resolution and speed due to ever faster production cycles and new CMOS sensors calls for cameras with increased transmission bandwidth.

Engineered for imaging applications that require high-speed data transfer, these new Nano models are an easy replacement for cameras built into current vision systems that rely on the existing GigE vision interface standard. These new Genie Nano models feature the brand new 5GBASE-T link speed.

IEEE 802.3bz-2016 is the expanded standard for Ethernet over twisted pair copper wire at speeds of 2.5 Gbit/s and 5 Gbit/s. This creates intermediate speeds between existing standards 1 Gigabit Ethernet and 10 Gigabit Ethernet. The resulting standards are named 2.5GBASE-T and 5GBASE-T. 5GBASE-T technology allows Ethernet links to offer greater flexibility with new data rates of up to 5Gbps over commonly deployed Cat5e cabling. The technology boosts data throughput of up to 100 meters through twisted pair copper cabling.

10 Gigabit Ethernet allows for transmission of 10 times more image data at 1.1 GB/s while at the same time providing all the advantages of Gigabit Ethernet interfacing without requiring a change to integration software.

The 10 GigE interface provides stronger solutions for applications requiring high bandwidth for long-distance transmission up to 100 m with a single cable, but eliminates the need for specialized components such as frame grabbers.

Under the label 10GBase-T, the Ethernet standard IEEE 802.3an defines the use of twisted pair cables. CAT6 cables are allowed for up to 55 m distance. Greater distances call for CAT6a cables.

Modern CMOS sensors offer excellent image quality at high sensitivity, low dark noise and a very high dynamic range at high frame rates. Together with the5 GigE and/or 10 GigE interface, these benefits display their strength in fast processes such as in video applications with up to 4K at 60 fps as well as in motion analysis and in virtual reality applications.

Compared with Gigabit Ethernet cameras, 5 GigE/10 GigE cameras significantly reduce overall system latency – i.e., the delay between the host‘s request and receipt of response. First, sensor reading is much faster which means shorter readout times, and finally the 10 GigE interface speeds up data transmission. The latency also depends on utilized hardware and software components. Unlike Gigabit Ethernet with 50 to 125 μs, the latency per frame is brought down to approximately 5 to 50 μs.

More and more PC motherboards support the 10GBase-T interface for direct implementation of 10 GigE cameras. Alternatively, low-priced 10GBase-T standard network cards allow for easy one-cable solutions with data and power (Power over Ethernet) over the same cable. However, Camera Link or CoaXPress always require an additional frame grabber card.

From GigE Vision Standard version 2 onward, changing the application software during the camera integration is a thing of the past, since the software is fully separated and autonomous from the Ethernet interface. Programming using GenICam remains the same, and operation together with GigE Vision cameras is easily achievable.