SHM-B Async

3.Check the path of your four-wire circuit for potential sources of interference (fluorescent lighting, electrical motors, etc.). Such sources of electrical “noise” can provide an environment in which unwanted signals are induced onto your four-wire circuit. Also, check to see if an adjacent four-wire cable carrying a separate data stream is creating “crosstalk.” It may be that the data signal is jumping from the adjacent cable onto the four-wire circuit between the two SHM-B modems (another type of induced signal).

•While you are checking your cable for sources of noise and crosstalk, check the cable for irregularities in the shield. Also, reconsider the cable’s ratings for attenuation, capacitance, and impedance. You may need to install a higher- quality cable for your particular installation.

•Your AC power source may be the culprit. Check your AC power at the wall socket and confirm that it is within the range given in Chapter 1.