CTrans OL CAN Fiber Optic transceiver provides transparent transmission of CAN signals between copper based sections via an optical fiber.
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 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):
- PMMA Connectors (up to 40m)
- ST Connectors (up to 1000m)
Three LEDs on the front panel indicate the status of the internal power and whether a signal is received on the CAN or fiber optic connection.
Key Product Features
- Coupling of CAN systems by optical fiber
- Available for PMMA and glass fiber, connection by pluggable connector or ST
- Protocol transparent; CAN error handling mechanisms are preserved
- Choice of baud rate: 10/20/50/125/250/500kBaud (selected at order time via factory set inhibit time)
- Extended error suppression
- LEDs to indicate status
Baud Rate Settings & Overall Cable Length Restrictions
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 with a pair of CTrans OL added When a pair of CTrans OL fiber optic transceivers are used, the effect of the propagation delay through the transceiver must be included in the cable length calculation. For a pair of CTrans OL transceivers, the typical and maximum propagation delays is 125ns 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. |
| 500kbit/s | 100 – 55 = 45m |
| 250kbit/s | 250 – 55 = 295m |
| 125kbit/s | 500 – 55 = 395m |
| 50kbit/s | 1000 – 55 = 945m |
Specifications
Layout and Connection
CTrans OL devices include one CAN segment (marked ‘CAN’) fed to a three pin pluggable terminal. Power is connected at a two pin pluggable terminal. The optical connection is type dependent either pluggable for PMMA or ST for glass fiber.
Limiting Values
| Parameter | Minimum | Maximum | Unit |
| Storage temperature | -30 | +80 | °C |
| Operating temperature | -20 | +60 | °C |
| Supply voltage | -100 | +35 | V |
| Voltage on bus connections | -30 | +30 | V |
| Admissible power consumption (at 60°C) | n.s. | 2000 | mW |
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.
Nominal Values
| Parameter | Minimum | Typical | Maximum | Unit |
| Current consumption (running idle) | n.s. | 30 | n.s. | mA |
| Current consumption (250 kBits/s, 100% busload) | n.s. | 40 | n.s. | mA |
| Supply voltage | 10 | 24 | 30 | V |
| Propagation delay (per pair of devices) | n.s. | 125 | 300 | ns |
All values, unless otherwise specified, refer to a supply voltage of 24V and an environmental temperature of 20°C.
