The IPMT-3 is a precision attenuator used to test IP video systems to ensure that you have an adequate digital signal margin. Digital signal margin is the amount of signal level above the digital cliff that you have in your system to prevent a picture failure from occurring. IP cameras will give you a perfect picture until the network cable loss reaches beyond the minimum allowable signal level and then you suddenly get no picture at all. This effect is called the digital cliff, because like walking off of a cliff, everything is great till you take the last step off the edge and then all is lost.
When you install an IP camera particularly when the network cable run is long, you need to know how close your system is to the cliff. This test is easy to do, just temporarily insert the margin tester’s 1dB and 2dB port in series using the short supplied jumper cable for a 3dB margin test, then connect it into the IP video line and see if you get a video image. If you have at least 3dB of margin you can rest assured that the system will operate even when the network cable loss varies with time and weather. If the video does not come on then the margin is below 3dB, next plug into the other ports one at a time to see how low the signal margin is. The IPMT-3 will test from 1 to 7dB of margin one dB at a time.
If the margin is below 3dB you should consider amplification to get more margin for proper operation of the system. In this way you can be certain that the system you installed is not near the digital cliff waiting for a small change in cable loss to fail.
Besides changes in network cable loss, the camera and recorders can be damaged by lightning and power surges that degrade the output levels of the equipment bringing it nearer to the digital cliff and causing intermittent operation of the system. These intermittent camera problems are hard to diagnose without knowing that the equipment output levels have dropped. If you are called to test an intermittent camera and it is working when you get there, use this unit to introduce additional loss to bring the camera info fail mode. Use this to determine if the problem is level related or some other problem.
Use this unit to test new and existing IP installations and to trouble shoot any intermittent camera operation. The unit comes complete with the IPMT-3 attenuator and two 6 inch straight IP network patch cables. This low cost tool is a must for anyone that installs IP cameras, put one in your toolbox today.
