Optical time domain reflectometer which measures an optical fiber with different wavelengths according to an order and collectively displays waveform data and a list of events for each waveform in the same screen

An optical time domain reflectometer (OTDR) comprising;

• light pulse generating means, connected to one end of an optical fiber to be measured, for selectively emitting light pulses having a plurality of wavelengths to the optical fiber to be measured;
• light receiving means for receiving a light reflected from the optical fiber to be measured and then outputting a signal corresponding to an intensity of the reflected light;
• storage means for storing a signal output from the light receiving means as waveform data for each of the wavelengths;
• arithmetic operation means for obtaining, by arithmetic operations, a position and Properties of an event based on the waveform data for each of the waveforms stored in the storage means;
• a display unit having a first display region and a second display region;
• and
• display controlling means for displaying the waveform data for each of the wavelengths stored in the storage means in the first display region of the display unit and also displaying in a list a position and properties of an event corresponding to each wavelength obtained by the arithmetic operations of the arithmetic operation means in the second display region of the display unit to thereby facilitate grasping of a difference in characteristics of an optical fiber caused by a difference in wavelengths on the list;
• allowable range setting means for beforehand setting an arbitrary allowable range for characteristic values of an event corresponding to each wavelength obtained by the arithmetic operations of the arithmetic operation means;
• and
• characteristic value deciding means for deciding whether a characteristic value of an event corresponding to each wavelength obtained by the arithmetic operations of the arithmetic operation means is within an allowable range set by the allowable range setting means,
• wherein the display controlling means displays a characteristic value, which is decided to exceed the allowable range by the characteristic value deciding means, in such a manner as to discriminate the above characteristic value from the other characteristic values.

An optical time domain reflectometer (OTDR) comprising:

• a connection terminal for connecting one end of an optical fiber line which is a test target;
• light pulse generating means, formed to selectively emit light pulses having mutually different wavelengths, for injecting the light pulses via the connection terminal to the one end of the optical fiber line;
• a light receptor for receiving a light injected from the optical fiber line to the connection terminal, and then outputting a reception light signal corresponding to an intensity of the received light;
• a memory for storing a series of waveform data pieces of the reception light signal output from the light receptor in a region corresponding to a wavelength of the light pulse, until a predetermined time elapses after one light pulse has been injected from the light pulse generating means to the one end of the optical fiber line;
• event detecting means for obtaining for each wavelength, based on waveform data for each wavelength stored in the memory, as an event occurrence position, a position where an intensity of a light proceeding from one end to the other end of the optical fiber line changes at least locally to calculate a characteristic value of the optical fiber line at the event occurrence position for each waveform;
• a display unit having a first display region and a second display region different from the first display region;
• waveform displaying means for displaying orthogonal coordinates consisting of a distance axis and an intensity axis of the light in the first display region of the display unit, and also collectively displaying, on the coordinates, waveform data for each wavelength stored in the memory;
• and
• event displaying means for displaying, in the form of a list in the second display region of the display unit, an event occurrence position for each wavelength detected by the event detecting means and a characteristic value at the event occurrence position for each wavelength;
• and
• waveform comparing means for comparing waveform patterns of events that have different wavelengths and occurrence positions within a predetermined distance range of event occurrence positions for each wavelength detected by the event detecting means to thereby decide whether the waveform patterns agree,
• wherein the event displaying means displays a plurality of events decided by the waveform comparing means that waveform patterns thereof agree in such a manner that it can be recognized that they are a common event occurring at the same position along the optical fiber line.

An optical time domain reflectometer (OTDR) comprising:

• light pulse generating means, connected to one end of an optical fiber to be measured, for selectively emitting light pulses having a plurality of wavelengths to the optical fiber to be measured;
• light receiving means for receiving a light reflected from the optical fiber to be measured and then outputting a signal corresponding to an intensity of the reflected light;
• storage means for storing a signal output from the light receiving means as waveform data for each of the wavelengths;
• arithmetic operation means for obtaining, by arithmetic operations, a position and properties of an event based on the waveform data for each of the waveforms stored in the storage means;
• a display unit having a first display region and a second display region;
• display controlling means for displaying the waveform data for each of the wavelengths stored in the storage means in the first display region of the display unit and also displaying in a list a position and properties of an event corresponding to each wavelength obtained by the arithmetic operations of the arithmetic operation means in the second display region of the display unit;
• allowable range setting means for beforehand setting an arbitrary allowable range for characteristic values of an event corresponding to each wavelength obtained by the arithmetic operations of the arithmetic operation means;
• and
• characteristic value deciding means for deciding whether a characteristic value of an event corresponding to each wavelength obtained by the arithmetic operations of the arithmetic operation means is within an allowable range set by the allowable range setting means,
• wherein the display controlling means displays a characteristic value, which is decided to exceed the allowable range by the characteristic value deciding means, in such a manner as to discriminate the above characteristic value from the other characteristic values.

An optical time domain reflectometer (OTDR) comprising:

• a connection terminal for connecting one end of an optical fiber line which is a test target;
• light pulse generating means, formed to selectively emit light pulses having mutually different wavelengths, for injecting the light pulses via the connection terminal to the one end of the optical fiber line;
• a light receptor for receiving a light injected from the optical fiber line to the side of the connection terminal, and then outputting a reception light signal corresponding to an intensity of the received light;
• a memory for storing a series of.waveform data pieces of the reception light signal output from the light receptor in a region corresponding to a wavelength of the light pulse, until a predetermined time elapses after one light pulse has been injected from the light pulse generating means to the one end of the optical fiber line;
• event detecting means for obtaining for each wavelength, based on waveform data for each wavelength stored in the memory, as an event occurrence position, a position where an intensity of a light proceeding from one end to the other end of the optical fiber line changes at least locally to calculate a characteristic value of the optical fiber line at the event occurrence position for each waveform;
• a display unit having a first display region and a second display region different from the first display region;
• waveform displaying means for displaying orthogonal coordinates consisting of a distance axis and an intensity axis of the light in the first display region of the display unit, and also collectively displaying, on the coordinates, waveform data for each wavelength stored in the memory;
• event displaying means for displaying, in the form of a list in the second display region of the display unit, an event occurrence position for each wavelength detected by the event detecting means and a characteristic value at the event occurrence position for each wavelength;
• waveform comparing means for comparing waveform patterns of events that have different wavelengths and occurrence positions within a predetermined distance range of event occurrence positions for each wavelength detected by the event detecting means to thereby decide whether the waveform patterns agree, wherein the event displaying means displays a plurality of events decided by the waveform comparing means that waveform patterns thereof agree, in such a manner that it can be recognized that they are a common event occurring at the same position along the optical fiber line;
• allowable range setting means for beforehand setting an arbitrary allowable range for the characteristic value;
• and
• characteristic value deciding means for deciding whether a characteristic value of an event detected by the event detecting means is within an allowable range set by the allowable range setting means,
• wherein the event displaying means displays a characteristic value, which is decided to exceed the allowable range by the characteristic value deciding means, in such a manner as to discriminate the above characteristic value from the other characteristic values.