Issues and questions when connecting a Midas DN4816-I and a Midas DN4888 to a PC via a Klark Teknik DN4816U with USB

[stufenbau]

Hi there

I have a StageConnect stage box that I occasionally want to use directly with my PC via USB. Upon connecting I made some observations which I do not understand. Maybe someone here can confirm this to be an intended behaviour or explain the reasons ... thanks already for any useful feedback.

The situation:
I have a working StageConnect stage box which consists of a Midas DN4816-I and a DN4888 (24x8). This stagebox ir normally connected to my Behringer Wing via the DN4816-I. Power is delivered to box devices via StageConnect via the DMX XLR cable of the Wing. All works as expected.

• Configuration on the DN4816-I: 0x16 (surprisingly not 16x0), Slave
• Configuration on the DN48888: 8x8, Individual

Both devices are updated to firmware v2.9.

Now, I got myself a Klark Teknik DN4816U so I could use this stagebox directly with my PC via USB. When I set the device to 24x8 via its push button I can select the device (in Reaper) via its ASIO driver to get all 24 inputs but in SimplyPUT the device is not recognised.

But here the part that I do not understand:

1. The DN4888 needs to be powered via its power supply.
2. This only works when the DN4888 is directly connected to the DN4816U.
3. SimplyPUT does not recognise the device (which means I cannot update the firmware) but the ASIO driver does.

( 1 ) I know from the DN4800 Series Quick Start Guide p15 that they also show the DN4888 as the first device after the console and they also show it to be powered. But both devices, Wing and DN4816U deliver 12V@1.5A via the SC connector (according to the specs). So, I do not understand why it only needs to be powered directly when connected to the DN4816U and not when I use it via the Wing.
[Edit 2024-03-16 20:18] I checked the specs of the both devices and according to the Midas web site their power consumption is 8.5W + 9W = 17.5W which is inside the expected output power of the DN4816U / StageConnect specificaton (12V * 1.5A = 18W). So, there should really not be any need for a second power supply.
I also tried with a different power supply and a 2nd DN4816U and different DMX cables with the same results.

( 2 ) Why do I have to connect the DN4888 as the first device in the StageConnect chain at all? Again, only when I use it via the DN4816U? The Wing automatically recognises both devices correctly regardless of their order.

( 3 ) I installed the latest Windows USB driver v5.30 and the device shows a "revision" of v1.00. Is there a special power on sequence or anything else to be done for the update?

Does anyone here has a working configuration with a DN4816U and DN4800 stage boxes who can explain or confirm this behaviour? Thanks for your help.

[stufenbau]

I am sorry to follow up on my question and give it another try ... Is there anyone using a DN4816U with StageConnect and willing to share his/her experience? Thank you for your support.

[pvannatto]

Hi @stufenbau, Sorry to hear that you are having issues with your StageConnect boxes. Unfortunately, I have yet to take the plunge and get any of these - still working with AES50 stageboxes. Hopefully someone will come along that have them and provide some help.

[GaryH]

Stage connect info. Most of this you probably already know but I think some of it answers a few of the questions-in how the SC system behaves. Feel free to disregard

There are two ways to configure an SC chain. Either you can manually configure the chain using devices like WING or let the Automatic Bus Configuration do its work. This process adapts the input and output configuration of the SC Bus depending on the connected devices. Simply connect devices and the Master device of the chain will automatically change the routing. To check and plan setups the SSC Tool software is available, providing information about the routing and DMX cable length, power management and other parameters.

The StageConnect Manifesto
1. There is always one Master device and up to 11 Slave devices in a StageConnect chain. 

2. The Master is always the first device in the chain. 

3. The StageConnect chain starts at an XLR male connector and ends with an XLR female connector.* 

4. Audio can only be transferred between Master and Slaves but not between Slaves and other Slaves. 

5. Audio outputs always come from the Master. 

6. Audio inputs are always sent straight to the Master.

7. The Master configures the StageConnect bus.

8. The first Slave unit after the Master has the highest priority.

9. Changes in the chain shall not be done on the run.**
*Just like a microphone connected to an analog input.
**This will interrupt audio for 2 seconds, while the bus is reconfigured.

EDIT:
I believe both the U and the 4888 can only output (send) power IF powered by their own dc adapter. They can be powered but not send power by SC alone. If they are desired to be mid SC chain somewhere AND also supply bus power downstream to other devices, they both would also need an adapter. Maybe it would be best if they are at the end of an SC chain (without an adapter) OR anywhere (including the beginning) with a power adapter so as to send power downstream. That would explain maybe some of the behavior you are seeing.

Maybe you need to connect the 4888 to a pc via usb directly to update firmware? Nothing else connected at all by SC or otherwise. A guess.

I was also thinking that maybe the 4888 can't pass its xlr inputs upstream by more than 8 ch.s? If that were true, it would make some sense that it be first in line after the mixer but just guessing here.The 4888 appears to be your master SC device and the Master device of the SC chain will automatically change the routing, The Master is always the first device in the SC chain. Have you tried using the SCC tool? It could maybe help you get the correct setup for your situation. If I get some time this week I will set up my SC stuff again and see what I can find out. I do have both those devices but have not used them in quite a while (I have no present need) They are not being used currently and sitting in a rack. This is a busy week for me unfortunately but this thread has me curious about SC once again.

[stufenbau]

Hi @GaryH and @pvannatto

Thank you for your answers and comments. I would like to clarify my setup based on the answer from @GaryH:

* I am powering the DN4816U with its own power supply. Nevertheless, it cannot power both StageConnect devices.
* SCC wants me to use a DC power supply in both setups Wing and DN4816U, but still that contradicts the spec sheet of the devices - see images below, and: the Wing setup is working without any power supply
* SCC shows either setup as working (DN4888 first/DN4816-I second or DN4816-I first/DN4888 second) - see images below

Here is a simplified "drawing" of my setup:

*** Working ***

Wing <-- 10m XLR/DMX --> DN4888 <-- 1m XLR/DMX --> DN4816-I
.........................^ not powered with external supply
...................................................^ not powered with external supply



*** Working ***

PC <-- USB --> DN4816U <-- 10m XLR/DMX --> DN4888 <-- 1m XLR/DMX --> DN4816-I
...............^ powered with external supply
...........................................^ powered with external supply
.....................................................................^ not powered with external supply



*** Not working ***

PC <-- USB --> DN4816U <-- 10m XLR/DMX --> DN4888 <-- 1m XLR/DMX --> DN4816-I
...............^ powered with external supply
...........................................^ not powered with external supply
.....................................................................^ not powered with external supply












I opened a support case with Klark Teknik to get their view on this. I will post an update when I get one.

Thanks anyway for your help.

[GaryH]

@stufenbau Both the U and 4888 supposedly can only pass power from their male xlr's if powered by an adaptor. They can receive it from other powered devices in the SC chain but not send it along without one. Are you saying that doesn't happen? Maybe new firmware has now changed how they work?

[stufenbau]

Hi @GaryH I tried to explain previously, but obviously did not make it clear enough. So, I try to summarise here:

* The DN4816U - which is powered itself via its standard power adapter - is able to power through its StageConnect socket a single StageConnect device (DN4888), just not both (DN4888 and DN4816-I). This conforms with the SCC "prediction" (see images from my previous post).

* But the Wing *can* power both StageConnect devices (DN4888 and DN4816-I) through its StageConnect socket *without* having either of them connected to a power supply. This does not conform with the SCC "prediction".

* Regardless of the SCC, the specs of DN4888 and DN4816-I state that the combined power consumption is *below* the power supplied by the StageConnect socket. So, it *should* work with the DN4816U - as it does with the Wing, where I do not need to power any connected StageConnect device (see my calculation in my previous/initial post).

Anyway, I will wait for KlarkTeknik to get their view on this and will share this here, in case anyone is interested. Thanks again for your help.

[GaryH]

@stufenbau I guess I wasn’t so clear either What I was trying to ask before regarding power (info taken from the user manuals) could still explain the behavior IF the 4816-I was the first thing connected out of the Wing and then from it to the 4888. That should work because the “I” can pass power received from the Wing via its SC male XLR. In your scenario did you by any chance ever connect it the opposite way? From Wing to the 4888 first, then to the “I”? That should NOT work without the 4888 being powered. If it does work without its adaptor then the manual (or my reading of it) is wrong, which is more than possible.

Same for the U setup scenario. It should power the “I” OR the 4888. But if in a chain and the 4888 was first connected to the U and then the “I” was connected to the 4888, it should not power the "I" without the 4888 power adapter plugged in. Again if you tried it the other way around, U first "I" second and then the 4888, the U I think should still power both. Neither the U or the 4888 is supposed to pass any power along the chain without being powered by an adapter. I am curious what KT says.

[stufenbau]

@GaryH It works when I connect the Wing as the only device powered in the following setup without any power adapters on the DN4888 and DN4816-I StageConnect devices:
Wing < -- > DN4888 < --- > DN4816-I

So, a StageConnect device (here the DN4888) does pass power to the next one even when it is not powered itself.

When I connect DN4816U < -- > DN4888 < --- > DN4816-I, I need to power both the DN4816U and the DN4888, otherwise the DN4816-I restarts every couple of seconds. When I connect DN4816U < --- > DN4816-I < --- > DN4888, I still need to connect power to DN4816U and either of the DN4XXX StageConnect boxes, but still the DN4816U does not recognise the devices (StageConnect light remains "red").

Mystery science theatre ...

[GaryH]

Indeed strange behavior! Thx. I guees we wait on KT