Safety signals
AssigneeAker Solutions AS
InventorsStephen Baxter, Robin Slater
Life of this patent
Estimating the term…
Abstract
A subsea system comprises a multiplicity of subsea installations (M-1 . . . M-n) and a common transmission line (2a) in an umbilical for the conveyance of power or data communication electrical signals to the subsea installations. The system provides on the common transmission line a plurality of safety signals (T-1 . . . T-n) in the form of tones separate in frequency from each other and the other signals on the line. Each subsea installation is arranged to receive from the common transmission line selectively a respective one of the safety signals for the control of a fail-safe device (9) in the installation.
Claims13
A subsea system comprising:
- a multiplicity of subsea installations;
- a first common transmission line configured to convey first electrical signals to the subsea installations, the system also being configured to convey on the common transmission line a plurality of safety signals in the form of tones separate in frequency from each other and from the said first electrical signals;
- a first bypass filter at each subsea installation arranged to selectively receive from said first common transmission line a respective one of the safety signals for control of a fail-safe device in the installation;
- a second common transmission line configured to convey second electrical signals to the subsea installations, wherein the system is also configured to convey on the second common transmission line a plurality of second safety signals in the form of tones separate in frequency from each other and from the said second electrical signals,
- at least a second bypass filter at each subsea installation arranged to selectively receive from said second common transmission line selectively a respective one of the second safety signals for control of the fail-safe device in the installation;
- and
- logic gates for the control of the fail-safe device in response to the respective safety signals from the first and second transmission lines;
- wherein the logic gates are disposed to put the fail-safe device in a fail-safe condition when either of the respective safety signals is inactive.
A subsea system comprising:
- a multiplicity of subsea installations;
- a first common transmission line configured to convey first electrical signals to the subsea installations, the system also being configured to convey on the common transmission line a plurality of safety signals in the form of tones separate in frequency from each other and from the said first electrical signals;
- a first bypass filter at each subsea installation arranged to selectively receive from said first common transmission line a respective one of the safety signals for control of a fail-safe device in the installation;
- a second common transmission line configured to convey second electrical signals to the subsea installations, wherein the system is also configured to convey on the second common transmission line a plurality of second safety signals in the form of tones separate in frequency from each other and from the said second electrical signals, and
- at least a second bypass filter at each subsea installation arranged to selectively receive from said second common transmission line selectively a respective one of the second safety signals for control of the fail-safe device in the installation;
- wherein each subsea installation is disposed to provide a first drive signal in response to the said first electrical signals and a second drive signal in response to the said second electrical signals and includes logic gates for the control of the fail-safe device in response to the first and second drive signals and the respective safety signals from the first and second transmission lines.
Dependencies are inferred from the claim text.