Mini delta ribbon (MDR) and shrunk delta ribbon (SDR) cable assemblies are both designed to carry video signals as specified in the Camera Link (CL) specification, and they have the same internal connections.
MDR and SDR cables are incompatible with the higher speed Camera Link HS (CLHS) standard. CLHS connectors include CX4 and SFP/SFP+.
A Basic CL connector has 5 low voltage differential signal (LVDS) pairs for the serialized video data and for framing/enabling, plus 2 LVDS asynchronous serial communication channels for connecting with the camera and 4 LVDS discrete control signals.
The CL chipset has a maximum operating frequency of 85 MHz. At that frequency, the Base version of CL, which uses a single cable connection, transmits video data at a maximum rate of 2.04 gigabits per second (Gbps).
MDR was the first connector for CL. The differences between MDR and SDR are their size and the transmission speed they support. SDR connectors are smaller than MDR connectors and tend to have slower data rates (Figure 1). They were developed for machine vision applications that require a compact solution and need CL performance.
Camera power
Power over Camera Link (PoCL) is a standard feature that allows a camera to be powered by a frame grabber through a CL cable. PoCL can deliver up to 4 W (400 mA at 10 V or 333 mA at 12 V) per CL cable. It eliminates the need for a separate power supply and reduces the cables needed on the back of the camera, shrinking the application footprint.
In the original 26-pin CL specification, pins 1, 13, 14, and 26 are ground. In PoCL, pins 1 and 26 carry power (Figure 2). Space-constrained designs can turn to PoCL-Lite for a smaller 14-pin solution. The PoCL-Lite connector is either SDR26P or SDR14P to support compact cameras.
Range extenders
While the CLHS includes an option for fiber optical interconnects, range extenders have been developed for standard CL that use fiber optics to support longer transmission distances. Various designs are available, with ranges of up to 80 km over single-mode fiber and 400 m using multi-mode fiber.
Range extenders solve the distance limitations of standard CL designs. CL Base cables are limited to a maximum of 10 m. For the other versions of CL (Medium, Full, and Deca), the maximum cable length is 5 m at 85 MHz, 7 m at 66 MHz, and 10 m at 40 MHz.
Range extenders use converters on either end to convert between standard MDR cables and the fiber optic link. As a result, the converter on the camera end can support a PoCL connection to power the camera through the MDR cable.
The range extender system uses SFP+ connectivity and can provide up to 10 Gbps bandwidth. It supports CL Deca (80-bit) transmissions with an 85 MHz clock over long distances. Some range extenders are rated for the full industrial operating temperature range of -40 to 85 °C.
References
Camera Link Cable Assemblies for Machine Vision (PoCL Lite), Hirakawa Hewtech Corp.
Camera Link Standard, Association for Advancing Automation
Shrunk Delta Ribbon (SDR) Cable Assembly, DigiKey
Shrunk Delta Ribbon (SDR) Connector and Cable Assembly, 3M
Understanding Different Camera Link Connector Types, Phase 1 Technology
Related links
e-con Systems launches high-resolution multi-camera for NVIDIA Jetson Orin
High-resolution multispectral line scan camera
How the digital-interface standards for cables and connectors are changing
Ultra-low-power platform brings automatic image recognition to IoT
Leave a Reply
You must be logged in to post a comment.