Hi Oskar-Luxonis, thank you for the response.
[T]he OAK 4 S negotiates power through IEEE 802.3at Type 2 physical classification before the OAK App starts.
Question: Does the OAK 4 S use data link layer classification, in addition to physical layer classification? (Additional information below)
Providing the requested information:
switch model, firmware version, [and] per-port PoE status
One of the switches we have observed the behavior on is an HPE Aruba Networking 2930F series (SKU JL258A) switch. They are using firmware version 16.10.
The switch only has two devices connected to it, two OAK 4 S W's. Both exhibit the same behavior (see next section).
The logs looked like this:
W 08/26/26 05:29:11 00563 ports: port 8 PD MPS Absent indication.
W 08/26/26 05:29:11 00562 ports: port 8 PD Over Current indication.
I 08/26/26 05:29:11 00565 ports: port 8 PD Removed.
I 08/26/26 05:29:12 00077 ports: port 8 is now off-line
W 08/26/26 05:29:12 00562 ports: port 8 PD Over Current indication.
I 08/26/26 05:29:17 00560 ports: port 8 PD Detected.
I 08/26/26 05:29:17 00561 ports: port 8 Applying Power to PD.
I 08/26/26 05:29:19 00076 ports: port 8 is now on-line
Those events would repeat/loop. Basically, the port/device comes online, it encounters an over-current event, power is removed from the port, power is re-applied, [repeat].
If we disable the OAK App we use on the OAKs, the switch does not kill power to their ports. That makes sense to me. The devices are being allocated 15.4 W (Class 3), which is sufficient for an "idle" OAK.
With the OAK App disabled, using the show power-over-ethernet <port> command, the LLDP Information section shows
LLDP Information
PSE Allocated Power Value : 13.0 W PSE TLV Configured : dot3, MED
PD Requested Power Value : 0.0 W PSE TLV Sent Type : dot3
MED LLDP Detect : Enabled PD TLV Sent Type : n/a
Note that is only a portion of the command's full output. I will need to work with a member of our client's IT department to get the full command output. They provided the LLDP Information section, stating that it shows the OAK is not responding to LLDP negotiations.
The relevant manual is here: https://support.hpe.com/hpesc/public/docDisplay?docId=a00091307en_us&docLocale=en_US. Pages 108 - 112 detail the show power-over-ethernet command.
[W]hether the OAK flashes red during startup
I do not know. I will work with someone on-site to check this. The OAKs are deployed at a location with a client. It is "remote" for me, but the client has personnel on-site.
If possible, please also test one affected OAK with another known-good PoE+ switch or injector.
As a temporary fix, we have added standalone PoE+ injectors for the OAKs. The OAKs are able to run the OAK App with that setup. (So, they are only receiving data from the switch; no power.)
I am interested in what your response will be, but my current guess is that we'll need to follow the guidance on page 114 of the manual: disable DLC with no lldp config <port> dot3TlvEnable poeplus_config. The behavior described on that page seems to match what we are seeing:
The default switch configuration always power demotes all Class 4 and above DS PDs to Class 3 power at PLC. It requires successful LLDP dot3Tlv 29 octet power negotiation through DLC
Since LLDP negotiation is not occurring, we're stuck at Class 3.
Thank you for your time. Please let me know if anything I have typed doesn't make sense. This is not my area of expertise, so I'm reading documentation to learn things.
