Technical notes

It is possible to combine Qualisys devices in a system in many ways. However, there are some technical limitations related to the type of cables used, the power requirements of the cameras and the bandwidth. The technical aspects of connecting different types of cameras are summarized below.

Power and camera cable requirements

  • Inter-chain mixing
    Cameras using the same cable type can be mixed together in a chain, without the need of a network switch. To mix cameras of different cable types you need to use a switch. For an overview of cable types, see the Table below.

  • Power kit capacity
    Due to varying power consumption, the number of cameras a power kit can power depends on the camera type and cable length. For an overview of the maximum number of cameras per power kit and the maximum total cable length per chain, see the Table below.

  • Maximum chain sizes in homogeneous systems
    The number of cameras that can be connected in a single daisy chain is limited. The maximum chain size per camera type is indicated in the Table below. To build a camera system with a larger number of cameras you need to use multiple chains, which are joined together with a network switch.

  • Maximum total cable length
    The maximum total cable length per power supply is limited for Arqus and Miqus systems. The maximum length depends on the type of power supply used. For the revision 2 (R2) power supply, the maximum cable lengths are displayed in the Table below. For the revision 1 (R1) power supply, the maximum total cable length is 50 m for Arqus and 120 m for Miqus systems.

    Older Miqus cameras are not compatible with the R2 power supply. Please contact Qualisys support for more information.

    Camera type Cable type Max. power kit
    capacity    		 Max. chain
    size    		 Max. total cable
    length [m]

    Arqus

    		 A 5 20 75

    Arqus Protected

    		 B 5 20 75

    Miqus

    		 A 10 20 140
    Miqus Video A 101 32 140
    Miqus Hybrid A 101 3 140
    Oqus C 5

    15

    		 -

    1Even though a power supply can power up to 10 Miqus Video/Hybrid cameras, it is
    recommended to use one power/data chain per three cameras.

    2When combined with marker cameras, the maximum number of Miqus Video cameras
    is 2 per chain.

    You can add a Camera Sync Unit to the chain beyond the maximum power kit capacity or maximum chain size.

Mixing Arqus and Miqus

Arqus and Miqus cameras can be mixed in the same chain. Due to differences in power consumption, one Arqus camera can be interchanged by two Miqus cameras and vice versa. Supported combinations per power kit:

  • 4x Arqus + 2x Miqus

  • 3x Arqus + 4x Miqus

  • 2x Arqus + 6x Miqus

  • 1x Arqus + 8x Miqus

Adding Miqus Hybrid or Miqus Video cameras

Power consumption wise, a Miqus marker camera can be swapped out for a Miqus Hybrid or Miqus Video camera. However, due to bandwidth requirements it is recommended to limit the number of video cameras in a chain to a maximum of two video cameras.

If more video cameras are needed, they should be added in a separate chain and joined through a network switch.

If you need more than three video cameras, the faster 10 Gigabit switch is required.

Connecting a Qualisys system through an Ethernet switch

For most systems the recommended setup is a daisy chain configuration. However, Qualisys systems can also be connected through an Ethernet switch. The use of a switch allows for more flexibility in setting up and combining Qualisys devices. The switch should have a bandwidth of at least 1 Gigabit. For systems with more than three Miqus video cameras a 10 Gigabit switch is required. The Ethernet cables must be Cat 6A or better.

To setup the system with an Ethernet switch, follow these instructions:

  1. Check that the computer has an Ethernet card with at least the same bandwidth as the switch.

  2. Connect the Ethernet card with the switch. You can use any of the ports on the switch.

  3. Use the standard network card settings as described in the chapter Network card setup.

  4. Connect the respective daisy chains of Qualisys devices to one port each.

Do not connect the different daisy chains to each other. It will disrupt the communication and the switch will be of no use.

The use of a switch is required in the following cases:

  • Large camera systems
    When the number of cameras in a system exceeds 20 for Arqus and Miqus or 15 for Oqus, the daisy chains should be split up in smaller chains.

  • More than two Qualisys video cameras in a system
    When there are more than two video cameras in a Qualisys system a switch is needed for optimizing the data communication. For Oqus high-speed cameras, the fetching time can be greatly reduced by connecting a maximum of 2-3 cameras per port.

  • Systems with more than three Miqus Video or Miqus Hybrid cameras
    This type of setup requires a 10 Gigabit switch with a maximum of three cameras per port.