Changes between Initial Version and Version 1 of poe


Ignore:
Timestamp:
10/22/2017 05:28:45 AM (23 months ago)
Author:
trac
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • poe

    v1 v1  
     1[[PageOutline]]
     2
     3= Power Over Ethernet (PoE) Notes =
     4
     5PoE works by having a PoE switch.  When the switch connects to a device, the switch tries to make a handshake with the device.  The device has to have the signature to be able to do the handshake to activate PoE.  Some Gateworks boards do not have this signature.   If the signature is not detected, then power is not turned on.
     6
     7''' Please reference the user manual for the product to learn if it has POE capability at [http://www.gateworks.com/usermanuals]
     8
     9Specs:
     10 * 802.3af-2003 standard provides up to 15.4W of DC power (min 44Vdc and 350mA) to each device.  Only 12.95W is assured to be available at the powered device (as some power is dissipated in the cable)
     11 * 802.3at-2009 standard (PoE+) provides up to 25.5W of power and prohibits a powered device from using all four pairs for power.  Some vendors have products that offer up to 51W by utilizing all four pairs.
     12
     13References:
     14 * http://en.wikipedia.org/wiki/Power_over_Ethernet
     15
     16== Online Shop ==
     17[http://shop.gateworks.com/index.php?route=product/category&path=70_73 Gateworks Shop POE]
     18== Passive PoE ==
     19
     20Most of our products support what is typically referred to as 'Passive PoE' as power is applied to the same pins defined in 802.3af however the intelligent signalling/detection is not present.  We do this because 802.3af DC range is only 37-60V and our customers typically want lower ranges.
     21
     22Issues:
     23 * GW2350/GW2351 have the TVS array on the input side of the mags thus will short power to gnd if a GigE passive PoE is used on these 10/100mbps board
     24
     25 === GW10022 ===
     2610/100 Passive Injector
     27||= Pin =||= Description =||
     28|| 1     || TX+  ||
     29|| 2     || TX-  ||
     30|| 3     || RX+  ||
     31|| 4     || VDC+ ||
     32|| 5     || VDC+ ||
     33|| 6     || RX-  ||
     34|| 7     || VDC- ||
     35|| 8     || VDC- ||
     36 === GW10054 ===
     371 Amp Gigabit Injector
     38
     39
     40
     41== 802.3af ==
     42802.3af is the 2003 standard for intelligent Power Over Ethernet.
     43
     44Gateworks boards with true 802.3af support:
     45 - GW2357
     46
     47== Emulated 802.3af ==
     48True 802.3af is costly and difficult to co-exist with passive PoE, so Gateworks designed a circuit that emulates it by providing the 'signature' needed to make an 802.3af PoE compliant switch enable power.
     49
     50While the 802.3 spec calls out the power pins explicitly it does not call out polarity because it also requires full rectification (which makes polarity a moot point). This created the fact that some products use one polarity and others use opposite with regards to + and - voltage rails (see here http://pinouts.ru/Net/poe_pinout.shtml). Some of our emulated 802.3af products do not have this full rectification for space reasons which can make them in-compatible with PoE on some devices without the use of a 'cross-over cable'.
     51
     52Gateworks Devices supporting this 'emulated' 802.3af:
     53||= GW BOARD =||= Full Rectification =||= Signature =||= Notes =||
     54|| GW2380     || no || no, passive only || Only supports passive voltages up to 42V ||
     55|| GW2382     || no || no, passive only || Only supports passive voltages up to 42V ||
     56|| GW2386     || yes || yes, 802.3af || Jumper W1 selects passive (ext) vs 802.3af (std) voltage range ||
     57|| GW2387     || yes || yes, 802.3af || Jumper W1 selects passive (ext) vs 802.3af (std) voltage range ||
     58|| GW2388     || no || no, passive only || Both Ethernet ports support passive PoE, use GW16090 for signature ||
     59|| GW2391     || yes || yes, 802.3af || Jumper W1 selects passive (ext) vs 802.3af (std) voltage range ||
     60|| GW54xx     || no  || yes, 802.3af || Jumper W1 selects passive (install) vs 802.3af (remove) voltage range ||
     61|| GW53xx     || no  || yes, 802.3af || Jumper W1 selects passive (install) vs 802.3af (remove) voltage range ||
     62|| GW52xx     || no  || yes, 802.3af || Jumper W1 selects passive (install) vs 802.3af (remove) voltage range ||
     63
     64Some of the above products feature a jumper 'W1' which enables 802.3af emulation ULVO (under voltage lockout). This jumper needs to be in the correct position (or removed) see above table depending on the board and whether or not you want passive PoE or 802.3af emulation.
     65
     66The following switch products use the opposite polarity that Gateworks uses and thus requires either a) a fully rectified emulation (see above), b) a crossover cable, c) a [http://shop.gateworks.com/index.php?route=product/product&product_id=129 GW16090] revB+:
     67 * D-Link DGS-1008P
     68 * Cisco SG100D-08P 8-port PoE switch
     69 * !ZyXel GS1910-24HP
     70
     71
     72[=#gw16090]
     73== GW16090 GigE 802.af/at to GigE passive PoE Adapter ==
     74[http://shop.gateworks.com/index.php?route=product/product&product_id=129 Purchase Here]
     75The Gateworks GW16090 allows boards that have no 802.3af/at support to be powered by an 802.3af/at switch or boards that only support 802.3af to be powered by an 802.3at switch. The GW16090 uses the Maxim MAX5969B PoE PD Interface Controller which provides both 802.3af and 802.3at signatures to the PSE device. For more info on the controler see: http://www.maximintegrated.com/en/products/power/switching-regulators/MAX5969B.html
     76
     77This product has been validated using:
     78 * Netgear FS-108P 10/100mbps switch (802.3af)
     79 * D-Link DGS-1008P 1000mbps (802.3af)
     80 * Cisco SG100D-08P 1000mbps (802.3af)
     81 * !ZyXel GS1910-24HP 1000mbps (802.3af/at)
     82
     83Notes:
     84 * Prior to revB only half wave [wiki:poe#Emulated802.3af 802.3a emulation] was supported.
     85 * Prior to revD only [wiki:poe#Emulated802.3af 802.3a emulation] was supported.
     86 * It is critical that any external connections (eth, jtag, serial, etc) to the product being powered by the GW16090 are electrically isolated.  Otherwise ground-loops can occur causing power failure at the switch and possible board damage.  This is particularly an issue with PoE switches that use !Power/Ground polarity opposite of what Gateworks uses for Passive PoE.
     87
     88
     89[=#testing]
     90= POE TESTING =
     91802.3af test matrix:
     92||= GW BOARD   =||= Netgear FS108P (48V, 1.25A) =||= D-Link DGS-1008P (48V, 1.25A) =||= Cisco SG100D-08P (48V, 1.25A) =||= !ZyXel GS1910-24HP (50V, 10A) =||
     93||GW2357        || PASS               || PASS               ||                     || ||
     94||GW2386        || PASS               || PASS               ||                     || ||
     95||GW2387        || PASS               || PASS               || PASS                || PASS                ||
     96||GW2391        || PASS               || PASS               || PASS                || PASS                ||
     97||GW5XXX        || PASS               || requires crossover || requires crossover  || requires crossover  ||
     98||GW16090-D     || PASS               || PASS               || PASS                || PASS                ||
     99
     100
     101=== Switches tested ===
     102 1. Netgear FS108P - 8 port 10/100 switch Standards:IEEE 802.3i  802.3u  802.3x  802.3af
     103 2. D-Link DGS-1008P - (requires cross-over for Ventana) Standards:IEEE 802.3/3u, IEEE 802.3af
     104 3. Cisco SG100D-08P - (requires cross-over for Ventana) Standards:IEEE 802.3/3u/3ab, IEEE 802.3af
     105 4. !ZyXel GS1910-24HP (requires cross-over for Ventana) Standards:IEEE 802.3af/at