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DM endpoints power
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We have DM-MD8x8, with DMC-4K-C-HDCP2 inputs cards and DMC-4K-CO-HD-HDCP2 output cards, then DM-TX-201-Cs and DM-RMC-4K-SCALER-Cs¡¡ All DM endpoints are not getting power from our CISCO PoE+ managed Switch, SF302-08PP-K9. I tried connecting the touchpanel to that PoE switch and it gets power. Any idea? |
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Look up answer ID 5609 in online help.? On Jun 26, 2017 9:39 PM, "titoortiz21@... [Crestron]" <Crestron@...> wrote:
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What's not mentioned in Ans ID 5609 is that the output cards also have a jumper which enables PoE for the "non-compliant 802.3af compliant" (The DM 4K online training says Crestron are compliant) switches. Speak to TB - they can tell you which jumper to move. (Hint... it says "POE" on the board next to it). |
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Crap - you're right!? I breezed through the Answer ID, but I already knew about the jumpers.? Why, won't they update this? ? I should have posted to look at this thread:? Also note that there are jumpers on the inputs cards as well. On Tue, Jun 27, 2017 at 9:19 AM, oliver.hall@... [Crestron] <Crestron@...> wrote:
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Andrew Welker
The device is compliant. The issue has to do with which pairs the power is on. The power can either be on the unused pairs or on the data pairs. All powered devices (PD) can accept either scheme, but the power sourcing equipment (PSE) implements one or the other. The issue here is a mismatch between the scheme on the Cisco switch and where the POE input on the card is passing power through to the endpoint, which moving the jumpers corrects.
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Hi all, Which jumper should we remove or plug in? Do you have photos of those? Regards, On Jun 27, 2017 20:56, "Andrew Welker andrew.welker@... [Crestron]" <Crestron@...> wrote:
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Sorry if this is pedantic, but if the device (the output card in this case) can't transparently pass power by either mode A or mode B, then it's failing to deliver the goods. Given that the list of switches on Crestron's Answer ID includes some big names (I know, not always a mark of quality, or compliance) and we use HP switches which aren't on the list, but also fail the test, and the only "approved" PSE's on the list are all Crestron units, I think I'm going to call foul on Crestron here. The card should pass the POE is either mode, or at least put a sticker on there mentioning the jumper. |
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Andrew Welker
It does. It negotiates what voltage and current the device needs. However, per the spec, the powered device has to accept both mode A and Mode B types of power delivery. The power sourcing equipment doesn't have to support both. Mode A is typical for endpoint devices like network switches, while mode B is typical for midspan devices...like a DM ouput card or the DM POE supplies that Crestron makes, or other midspan devices. I am just glad that Crestron has supplied a way to change the mode for the cards relatively easily. They could have just left it as a mode B device.
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But - strictly speaking - the DM output card isn't a PoE Midspan device.? It injects power onto the 8G, and we're all on the same page in as much as Mode A or B is valid, and the PD deals with that, but it doesn't *provide* the power.? That's being delegated to an external device (I wish it wasn't!).? On the power side, the DM card is acting as a repeater, so it's both a PD *and* a PSE.? The PD element isn't compliant (by your own argument) as it doesn't accept either power mode. I agree, it's relatively trivial to correct any mis-match, but that's predicated on this information being widely known:? At the moment this is one of Crestron's best kept secrets.? It's not documented, certain elements of TB don't know about it, and our account manager was completely unaware.? Changing jumpers on boards isn't really a great solution for most dealers either - it wasn't even that long ago that Crestron didn't support field swaps of output cards. |