Product Support

POE Troubleshooting

Most ACTIV POE issues clear up by unplugging the filter and plugging it back in. If that doesn't fix it, the steps below walk through the most common causes in order, including PoE-specific checks for downstream devices that aren't powering up. Try them in order.

Installation Guide

Before You Troubleshoot

The ACTIV POE only works with Ethernet (the kind of network signal that carries internet, IP phones over data networks, file sharing, and so on; technically called TCP/IP). It will not pass cable tester signals, certain phone systems, or other equipment that uses the same kind of cable but isn't actually Ethernet. The only real way to test the filter is to put it between two devices that you know speak Ethernet to each other and confirm they can still talk.

The ACTIV POE delivers Power over Ethernet to the device on the protected side of the filter. The network side of the filter expects standard Ethernet (no PoE injection from the network). If your network switch is already a PoE switch, the ACTIV POE ignores the network-side PoE and supplies its own to the protected device.

Troubleshooting

Step-by-step diagnosis

Try these in order. Most issues are resolved by Step 1 or Step 2.

Step 1

Unplug the filter and plug it back in.

This step solves most issues, and it confirms the filter is receiving power and delivering PoE to the downstream device.

This solves most problems. The ACTIV POE is powered through a small DIN connector on the filter. Unplug the DIN connector, wait about ten seconds, and plug it back in. Press firmly until the connector clicks fully into place. The Power LED (red) should come on right away. The PoE LED (on the protected side) should illuminate within a few seconds, indicating power is being delivered to the downstream device. The Link Speed LEDs on each side should light up as the filter re-establishes its connections.

If the Power LED does not come on after reseating the DIN connector, check that it's fully seated; the connector requires firm pressure to click into place, and a partial connection can prevent power from reaching the filter. If the Power LED still doesn't come on after a confirmed full seating, the issue is on the power side. The ACTIV POE uses a 24V / 3.75A adapter. If you have a multimeter, you can verify the adapter output reads 24VDC or slightly higher, but be careful when probing the DIN connector pins; the pins are close together, and while the adapter has built-in short-circuit protection, careless probing can produce misleading readings. If the adapter output is correct and the Power LED still doesn't come on, contact us; the filter may be faulty.

If the Power LED is on but the PoE LED on the protected side is not, power is reaching the filter but is not being delivered to the downstream device. Long cable runs cause voltage drop. PoE specifications allow up to 100 meters of CAT5e or better cable, but voltage drop on long runs can prevent power-hungry devices from receiving enough power at the far end. If your installation is near the 100 meter limit, try shortening the cable run between the filter and the connected device temporarily to confirm whether cable length is the issue.

Step 2

Reset the filter and the connected device together.

This step clears any stuck network address on the connected device that the filter reset alone won't fix.

If just resetting the filter didn't help, the device behind the filter may be stuck on a temporary network address it gave itself when the connection briefly dropped (called an APIPA address, in the 169.254.x.x range). Unplug the filter and turn off the connected device (or unplug the Ethernet cable from the connected device since it's likely powered by the filter). Wait ten seconds. Power the filter back on first, give it a few seconds to come up, then power on or reconnect the connected device. The connected device will request a fresh network address on startup and rejoin the network normally.

Step 3

Restart everything from the network side and working downward.

This step restarts the entire chain in the right boot order so each device connects to a healthy upstream connection.

If neither reset worked, restart everything starting from the network side and working downward. Power off the connected device, then the filter, then your switch or router. Wait ten seconds. Turn things back on starting from the switch or router, then the filter, then the connected device. Always from the network side downward, with each piece given a few seconds to come fully online before turning on the next.

Step 4

Check the cable connectors for bent or crushed pins.

This step rules out physical damage at the cable connectors before testing for cable or filter failure.

Look at both RJ-45 jacks on the filter and at the connectors on each cable. Make sure the metal pins are straight and even with no obstructions. If any look bent or crushed, the cable plug or the filter jack may be damaged. Reseat both cables firmly. If you suspect a cable, swap it for one you know works.

Step 5

Bypass the filter to confirm the cables and the network are good.

This step verifies the cables, the network, and the connected device are functional on the data side. If they all pass and the filter still doesn't, the filter is the cause. (PoE isn't tested here because the bypass removes the PoE source.)

Unplug both cables from the filter and connect them together with an RJ-45 coupler. The downstream device will not receive power in this configuration (you've removed the PoE source), but you can confirm whether data is passing through the cables and the network. If data passes through the bypass but not through the filter, the filter needs to be replaced. If data still doesn't pass, the problem is one of the cables, the connected device, or the network, not the filter.

If you don't have an RJ-45 coupler, test each cable separately by using one cable to connect the network directly to the connected device. You may need to either use a longer cable or move the connected device closer to the network connection to do this. If the device reaches the network with one of the original cables, that cable is fine; test the other the same way.

Step 6

Contact us.

If you've worked through Steps 1 through 5 and the filter is the cause, contact us. We'll arrange an RMA and take it from there. All ACTIV Ethernet filters carry a two-year warranty from the date of first sale. See the warranty page for details.

Common Questions

Common questions

I'm seeing a small amount of radio frequency emission coming from the filter when I scan the inside of my chamber or shielded room. Is something wrong?

A.The ACTIV POE is an active filter and produces a small amount of radiated emission. The filter is engineered to keep these emissions as low as physically possible, but you may be able to detect them. What can make the noise worse is improperly grounded cables. If you are using the short extension that came with the filter, the simplest fix can be to remove that extension and connect the device directly to the filter with a single cable. This may eliminate a poor ground. If you've done that and the emission is still visible, contact us with your measurement data and we'll work through it with you.

Does it matter which side of the shield wall the filter body is on?

A.The ACTIV POE is directional with respect to power. The PoE-powered device must be on the protected side of the filter. The data path is bidirectional, so either RJ-45 carries Ethernet equally well, but the filter body should be installed so the labeled output side faces the protected enclosure. Most installations put the body on the outside because that's where the power adapter sits.

My downstream device is a high-power PoE device (camera with PTZ, access point with multiple radios, etc.) and isn't powering up. What are my options?

A.PoE has multiple power classes. If the downstream device negotiates for more power than the ACTIV POE can deliver, it may refuse to power up at all rather than run partially. Check the device's PoE class requirement and confirm it's within the ACTIV POE's delivery budget. Long cable runs also cause voltage drop, which can drop a marginal device below its operating threshold. Try a shorter cable temporarily to isolate whether the issue is cable-related or class-related. If the device truly requires more power than the filter delivers, contact us; for some applications, providing the device with separate dedicated power and using the ACTIV POE for data only is a working alternative.

Does the type of CAT cable matter? Shielded versus unshielded?

A.For data, no. The ACTIV POE regenerates the Ethernet signal internally, so it doesn't care what kind of cable feeds it. For power, cable quality matters more. PoE delivers up to about 1 amp through the cable's conductors at full load, and lower-quality cables (especially the cheap CCA cables sold as "CAT6") have higher resistance and more voltage drop. Use solid copper cable, CAT5e or better, for any PoE run.

Need additional help?

Contact our engineering team for installation support, troubleshooting, or warranty service.