POE issue occurred on long cable
Posted: Thu Jan 28, 2016 12:08 pm
For months we had a mini powering two Netmetals from Mikrotik and sometimes a SXT. The power feed of the mini comes over a 48V POE-in supplied by an airmax power adapter over a ftp cable some 70 meters of length.
Last night we has to disconnect the power adapter to change the 220V socket block connected to a UPS to make room for a new router supply.
After the powering up we checked the working of the netonix and all was fine.
This morning we checked and found one of the ports of the mini didn't supply power to one of the net metals anymore since only some 15 mins after my check last night. (Log)
We rebooted the unit this morning, switched PoE off and back on for that port (4) to no avail..
Maybe a bug? I don't remember exactly what firmware version but maximal some weeks old (1.3.6 - 1.3.7?) Anyway, decided to upgrade to 1.3.8 and after that things spiralled downwards. Everytime the unit rebooted it itself reverted back to a state with the last config.
The unit became accessible over my network only for some secs. just long enough to disable all poe-out settings. Then the unit cycled and came up normally and stayed up.
The moment we tried to enable one, or two of the ports with the two Netmetals, the unit lost connectivity and rebooted back to the last working condition.
We went to the tower and tried the netmetals. They both work fine running on a small battery. We could connect them with direct (mobile battery pack) power on their ports of destination and just ethernet cable connected to the switch and all worked fine. Traffic flowed etc. The battery delivers 18V to the netmetals where the PoE-out of the mini was set for 24V.
We checked now the port 4 & 5 to see if it would power up the SXT radio, which it did on both ports without any problem. So on a SXT the ports work fine.
We replaced the mini for another off the shelf, same results. It does power the SXT on each port, but not the Netmetals on any.... (this one runs 1.3.7)
We finally displaced the mini for a MT-Switch that we used before (but removed because in gigabit it had issues) and that MT switch now powers the 3 units (2 x Netmetal + SXT) without any problem. This MT-Switch (rb260GSP) is fed by a normal non standard 24PoE that comes over the same cable and delivers the same 24V voltage to all units and works normal. Both Netmals are functioning.
Now I have the both tried mini's on my desk and they both seem to work fine. The are powered by the same airmax power adapter and both can power up 2 netmetals and a SXT and even another unit.
We also did test both mini's on the desk this morning similar but the moment they were put back in place at the tower couldn't power the NetMetals anymore???
The only difference between the tower and my desk is the length of the 'feed' ftp cable. This is a very static cable and even in the process of swappign units or its power there is little movement needed. On the present connected 24V PoE MT switch (half the voltage, thus double the amps over now only two pairs of wire) this cable works fine with stable (no package losses) Gigabit connection. So the cable is fine....
On the desk we obviously have short cable to feed the mini. Only 1 meter.
Tonight I will make a very long cable and just put that on my desk to feed the unit. See what happens. Apart from that we are clueless what might have happened that the units we put much confidence in and that ran for 7 months now suddenly don't do their job anymore!
If we can't fix the issue we are in despair since we planned several more similar switches to deploy in our presently ongoing network upgrade. Now these plans are halted until we know what happened.
Await your answers/ideas.....
Last night we has to disconnect the power adapter to change the 220V socket block connected to a UPS to make room for a new router supply.
After the powering up we checked the working of the netonix and all was fine.
This morning we checked and found one of the ports of the mini didn't supply power to one of the net metals anymore since only some 15 mins after my check last night. (Log)
We rebooted the unit this morning, switched PoE off and back on for that port (4) to no avail..
Maybe a bug? I don't remember exactly what firmware version but maximal some weeks old (1.3.6 - 1.3.7?) Anyway, decided to upgrade to 1.3.8 and after that things spiralled downwards. Everytime the unit rebooted it itself reverted back to a state with the last config.
The unit became accessible over my network only for some secs. just long enough to disable all poe-out settings. Then the unit cycled and came up normally and stayed up.
The moment we tried to enable one, or two of the ports with the two Netmetals, the unit lost connectivity and rebooted back to the last working condition.
We went to the tower and tried the netmetals. They both work fine running on a small battery. We could connect them with direct (mobile battery pack) power on their ports of destination and just ethernet cable connected to the switch and all worked fine. Traffic flowed etc. The battery delivers 18V to the netmetals where the PoE-out of the mini was set for 24V.
We checked now the port 4 & 5 to see if it would power up the SXT radio, which it did on both ports without any problem. So on a SXT the ports work fine.
We replaced the mini for another off the shelf, same results. It does power the SXT on each port, but not the Netmetals on any.... (this one runs 1.3.7)
We finally displaced the mini for a MT-Switch that we used before (but removed because in gigabit it had issues) and that MT switch now powers the 3 units (2 x Netmetal + SXT) without any problem. This MT-Switch (rb260GSP) is fed by a normal non standard 24PoE that comes over the same cable and delivers the same 24V voltage to all units and works normal. Both Netmals are functioning.
Now I have the both tried mini's on my desk and they both seem to work fine. The are powered by the same airmax power adapter and both can power up 2 netmetals and a SXT and even another unit.
We also did test both mini's on the desk this morning similar but the moment they were put back in place at the tower couldn't power the NetMetals anymore???
The only difference between the tower and my desk is the length of the 'feed' ftp cable. This is a very static cable and even in the process of swappign units or its power there is little movement needed. On the present connected 24V PoE MT switch (half the voltage, thus double the amps over now only two pairs of wire) this cable works fine with stable (no package losses) Gigabit connection. So the cable is fine....
On the desk we obviously have short cable to feed the mini. Only 1 meter.
Tonight I will make a very long cable and just put that on my desk to feed the unit. See what happens. Apart from that we are clueless what might have happened that the units we put much confidence in and that ran for 7 months now suddenly don't do their job anymore!
If we can't fix the issue we are in despair since we planned several more similar switches to deploy in our presently ongoing network upgrade. Now these plans are halted until we know what happened.
Await your answers/ideas.....