Approximate length that CAN Bus Active Flying Leads can reach at full subsea pressure (illustration: Teledyne Oil & Gas)

Teledyne Oil & Gas has added the CAN bus communication protocol to its Active Flying Lead product family. The subsea oil and gas industry has standardised to “fault tolerant” CAN bus communications for sensors and other subsea controls. This variation has a limited transmission distance for single node or sensor systems of only 40 metres. Teledyne has recently qualified three new configurations that extends the range of the CAN bus signal to up to 5,000 metres.

The Active Flying Lead product line is characterised by integrating specialised electronics into qualified highly reliable atmospheric housings located directly within a subsea cable, or flying lead. The ability to run CAN Bus signals longer than before allows for greater flexibility in the placement of sensors in an oil field or subsea observatory. The alternative is to locate a control pod near the desired sensor placement, or by modifying the sensor location, even though an alternative location may have been more effective.

The three new variations of Active Flying Leads include:

ECFL-FT – Fault Tolerant CAN Bus – The first variation electrically repeats the CAN signal. The CAN Repeater can double the original working distance with only one housing. For example, if 40 metres was original step-out length, then with the Repeater, the CAN jumper could provide transmission up to 80 metres.

ECFL-HS – High Speed CAN Bus – The second variation, which is also all electric, converts the “fault-tolerant” CAN bus into “high speed” CAN bus. The “high speed” variation of CAN bus uses a lower voltage which experiences less line loss over distance. The reduction in loss allows the signal to travel over 300 metres before being converted back to a “fault-tolerant” protocol. This version requires two housings to convert the signal and convert it back. This allows for a total distance of up to 380 metres.

EOFL-C – Optical Extended CAN Bus Jumper – The last option is an electrical to fibre optic conversion. One fibre is used to transmit and receive data. Two housings are used to convert the signal to and from fibre. The electrical section can each be up to 40 metres long. The CAN to Optical converter allows for distances up to 5 kilometres between CAN nodes or sensors.

Tags: Teledyne Oil & Gas