RMB meter bridge protocol inquiry


New member
Hi folks!

So, I'm a new user here but not new to ADAT, having used them since the 90s.

I've recently busted mine out of storage because, combined with my MOTU AVB interfaces' ADAT lightpipe in/out, they can serve not merely as excellent IO interfaces, but can also drive the Alesis RMB remote meter bridge (which I also own). It works - and It makes for an extremely ergonomic setup having 32 channels of metering in a 2 space rack - but doing so - going from the MOTU interface Lightpipe to the Meter Bridge's 4 RS-232 9-pin jacks - takes 4 ADATs, a whopping 12 rack spaces!

So I'm hoping to prototype a box, maybe driven using a raspberry pi or the equivalent, that can do these audio - meter functions in place of the tape machines. It would take the lightpipe in using a USBstreamer or the like, either 8 channels per processor or more, and convert the audio to the proper signals to drive the meter bridge directly from a USB rs-232 adapter(s). Alternately, it could built as an AVB listener, without Lightpipe, but that strikes me as more work than benefit given the rarity of RMB's.

That catches u up to my current question - like the sync protocol, is the ADAT RMB protocol even RS-232? even though it goes over 9 pin DIN, I am not sure whether it can be protocol analyzed, whether it's voltage, etc. - and I thought I would ask some experts. While getting it working w the ADATs serving the purpose was fun, replacing them w code and raspberry pi prototype is pretty new to me.

Thanks for any and all input and information that helps me understand whether I can replace the ADATs in the Lightpipe -> ADAT -> Meter Bridge connection with some software and hardware. I'm keen to make this as efficient as I hope it can be.