The merits of the different connection methods in relation to data rates (bandwidth), complexity and transmission lengths are discussed in detail in the camera and acquisition technology sections. This chapter talks about the issues and considerations when selecting the correct cable for an application, regardless of the interfacing method used.
The choice of cabling for an application is driven by the following considerations:
- Cable flexibility
- Transmission distance
- Connector integrity and material
- Cable routing
Most cables have a degree of flexibility, in that you can bend them to fit into a system chassis or machine. For applications where the camera will be moving, standard cables are not sufficient, as they are not designed to withstand continuous bending and flexing over time. In these applications robot or track-grade cables should be specified. These cables are tested with repeated movements to simulate use on a robotic system or drag chain. The parameters that define this type of cable are: the minimum radius angle of the flex and the number of flexes in a given time period.
Track-grade cables are typically designed to survive more than 1 million flexes with a minimum radius. Robotic-grade cables go through an additional torsional flex test which specifies repeated twisting of the cable through up to 360° over a specified length. This simulates the stress on a cable used in connection with robot arms. Most interface cables are available in higher flex formats.