Using the Tone Generator
The tone generator is used for fiber identification when an installer is faced with multiple unmarked links and the cable ends are not readily accessible by a single technician or are far removed from one another. The tone is inserted by the light source at one end of the link and identified at the other using the tone feature of the FPM 101.
In new installations, the link ends can be identified with the FLS 101 and FPM 101 using the WAVE ID feature and simply looking for the active link among the inactive links. However, in larger bundles that may have links carrying live data traffic, the tone generator in the FLS 101 can be used to identify spare links. The FPM 101 can differentiate between live traffic on fibers and the 2 kHz test tone generated by the FLS 101 to ensure a live fiber is not cut or disconnected causing a disruption of critical services.
To Quickly Identify a Fiber Optic Link
1.Connect the light source to one end of the link to be identified. Use the appropriate reference cable and coupler.
2.Select the 1550 nm wavelength using the SM button, then turn on the 2 kHz tone by pressing the tone button. The tone indicator LED lights.
3.On the other end of the link, if the bulkhead is not accessible, unplug the cables one at a time and connect them into the receive reference cable using a coupler. The cable that causes the 2000 Hz display to light is the desired cable.
NOTE: Cables with live data traffic are identified by their
wavelength and signal strength but they do not light
the tone display.
Identifying wavelengths is not instantaneous. Always wait a few moments for the FPM 101 to identify the signal.
Coupler
Coupler
Mark the cable ends for reference.
Clean the connectors and couplers often.
Receive
Reference
Cable
Transmit
Reference
Cable
FLS 101 |
1550 nm
19.46 dBm
2000 Hz
FPM 101
Figure 14. Tone Identification Connections
Fiber Optic Test Meters • Operation 16