I have multiple GigE Vision cameras that I would like to connect through a switch to a single Gigabit Ethernet port. Does NI-IMAQdx support this topology? Is there a limit of cameras that NI-IMAQdx can detect?I am using multiple GigE cameras through a switch but I'm seeing black frames or green bands during my acquisition.
Yes, NI-IMAQdx does support this topology. Because GigE Vision is an Ethernet standard you can generally use any network topology you want. Below are some possible topologies:
When multiple GigE Vision cameras share a single port, the bandwidth is shared between the cameras. NI-IMAQdx will detect all the cameras available on the network and it should work with your application as long as you have enough bandwidth to set the acquisition.
If you are concerned about bandwidth, performance from PCI express is better than PCI as it has a higher throughput. PCIe will allow you to use the entire Gigabit Ethernet bandwidth while transfer rates on a PCI card will be limited to the lower PCI bus speed. In an ideal system, the PCI bus has a capacity of 132MB/s but in a real-world system you will generally see transfer rates up to 90MB/s.
If the maximum bandwidth is exceeded, you will begin to experience data loss. This can be expressed in many ways, but it is most common to see black or green lines/bands flash across the image. To prevent data loss, the camera must be adjusted to use a smaller bandwidth. This is easily done in Measurement & Automation Explorer (MAX). With the camera selected, navigate to the Camera Attributes tab. Select View Options at the top, and then select All Attributes. Expand the attributes menus until you find the Desired Peak Bandwidth setting.
The image below shows what this setting looks like in MAX:
If you are using a topology that requires a switch it is recommended that the switch supports Jumbo Frames.This is also true for the Gigabit Ethernet network card as all hardware in the system needs to support Jumbo Frames so that the data will be transferred in the most efficient manner. If any component in your system does not support Jumbo Frames then you will be limited by the maximum packet size of this component.
Collaborate with other users in our discussion forums
A valid service agreement may be required, and support options vary by country.