CTrans OL acts as a CANBus converter / transceiver for protocol transparent transmission of CAN signals between copper based sections via an optical fibre.
Several technical improvements can be obtained by optical transmission of CAN signals, such as secure separation of high voltages and insensitivity to electromagnetic perturbation. Furthermore the transparent transmission of CAN signals with CTrans OL preserves the main benefits of CAN, such as error correction and priority driven bus access
Like repeaters the CTrans OL can be used to build flexible wiring topologies. Star and tree structures as well as stub lines can be realized. The integrated error suppression reduces the influence of faulty segments onto intact sections.
For the optical connection cost effective PMMA fibers with pluggable connection and 62,5µm multi-mode glass fibers with ST connectors are supported. Depending on the type of fiber a wiring distance up to 1000m can be achieved, subject to Baud Rate Settings & Overall Cable Length Restrictions (see section below):
Three LEDs on the front panel indicate the status of the internal power and wether a signal is received on the CAN or fiberoptic connection.
CTrans OL transceivers are available in a number of baud rate configurations. The maximum CAN cable length, which is the distance between the furthest two nodes in the network, is related to the operating baud rate as follows:
|Baud Rate||Maximum Cable Length (m)|
When CTrans OL transceivers and optical fiber are used, the effect of the propagation delay through the transceivers and fiber must be included in the cable length calculation.
For a pair of CTrans OL transceivers, the typical and maximum propagation delays is 150ns and 300ns, respectively. Assuming a 5.5ns/m propagation delay for cable, the maximum propagation delay through the transceivers is equivalent to a cable length of roughly 55m.
CTrans OL devices include one CAN segment fed to a three pin pluggable terminal. Power is connected at a two pin pluggable terminal. The figure shows the locations of power, CAN and fiber optical connections. Three LEDs on the front panel indicate the status of power, CAN and optical transmissions.
|Voltage on bus connections||-30||+30||V|
|Admissible power consumption (at 60°C)||-||2000||mW|
|Maximum fiber length (PMMA fiber / connectors)||-||40||m|
|Maximum fiber length (glass fiber / ST connectors)||-||1000||m|
Any (also temporary) stress in excess of the limiting values may cause permanent damage on CTrans OL and other connected devices. Exposure to limiting conditions for extended periods may affect the reliability and shorten the life cycle of the device.
|Current consumption (running idle)||-||30||-||mA|
|Current consumption (250 kBits/s, 100% bus load)||-||40||-||mA|
|Propagation delay (per pair of devices)||-||125||300||ns|
All values, unless otherwise specified, refer to a supply voltage of 24V and an environmental temperature of 20°C.