Multi-devices or sub-devices

[Fokko]

Hello,

I hope someone can help how a multi-channel dimmer should behave with RDM. We can choose between a root using 4 DMX slots, or a root using 0 DMX slots and 4 sub-devices each using 1 DMX slot.

In both cases we can only set the start DMX address, for all 4 dimmer channels, but it seems that this is allowed in both solutions.

Any thoughts?

[sblair]

A lot depends on what other features/parameters you have that you want to expose via RDM.

If it is just a basic dimmer pack with the main setting being a DMX address and the DMX addresses are contiguous for all the dimmers in the pack, then I would probably opt to chose handling it as a root device that uses 4 slots and not go the sub-device route.

If on the other hand you've got a larger rack that can have different types of dimmer modules with different settings/parameters such as module type, dimmer curve, current load, etc.. then sub-devices are the route to go.

[Fokko]

Thanks for your reply.

Well, we are in between; we have two personalities (8 or 16 bit dimming mode), and a current overload status for the whole pack (4 channels). But we also have temperature, and temperature overload status per dimmer channel.

Maybe the choice for sub-devices is not too bad, unless desk manufacturers can not easy handle sub-devices.

Fokko van Duin,
CDS advanced technology bv,
http://www.lanbox.com/

[sblair]

Sub-Devices were really created with Dimmers in mind, so I'd say it is the way to go. Since RDM is just getting out there, I'm not sure yet right now how well Sub Devices are being represented in controllers.

[wayne@artisticlicence.com]

Hi Fokko,

Picking up on the question re start address and footprint. We take the following approach:

1) Use sub devices if the product is modular.
2) When we set the start address of the root - it automatically sets all sub start addresses to consecutive patch from that address.
3) Even if the root has a zero footprint, we report to total sub device footprint.

Cheers

Wayne