Hi,
I’ve been controlling my Motif Rack from a Roland RD-700GX for years and never encountered a MIDI buffer full warning until I began to use a Kurzweil PC3LE8 as my controller. Now, any patch change on my Kurzweil will trigger the MIDI buffer full warning.

I have searched the Web for a solution, but all the MIDI buffer error message posts I have found have been with the ES or EX models in which the solution seems to be turning the MIDI soft through to off. Unfortunately, I cannot seem to find that mode on the Rack.
There is a Thru Port setting, but the only changes that can be made are setting it from 1 to 8, which I assume are MIDI channel settings.

Can anyone please tell me what I’m missing here?
Mark

There is a Thru Port setting, but the only changes that can be made are setting it from 1 to 8, which I assume are MIDI channel settings.

No, those are not MIDI channel settings. Those are MIDI THRU PORT settings. A PORT in MIDI is defined by 16 MIDI Channels traveling in two directions: 16 CHANNEL IN/16 CHANNELS OUT.

So two MIDI cables between two items defines a PORT.

A USB cable when working with the Yamaha USB-MIDI driver is capable, at maximum, of carrying 8 PORTS; that is 8 sets of 16 channels IN/OUT if you get what I’m saying. The Motif-Rack itself can use PORT 1 as its communication PORT with the computer (IN and OUT) “Yamaha Motif-R-1”.

PORT 2, for example, could be used for your PLG150-series Plug-in Boards if they were installed. By putting the PLG150 boards on their own PORT, MIDI messages could be sent from your computer on PORT 2, MIDI channel 1 (remember each PORT has 16 MIDI channels), a second PLG150 board could occupy MIDI channel 2 of PORT 2. And these would be totally discreet PORTs from the ones feeding the internal PARTs assigned MIDI channel 1 and 2 (because the internal PARTS are on PORT 1, not PORT 2).

The Motif Rack (unlike its keyboard counterpart) cannot be used as a REMOTE CONTROL surface for your DAW so some of the ports are not used. But you can imagine that a PORT could be designated to use the front panel of the keyboard version of the Motif to control a DAW - when placed in “REMOTE CONTROL” mode the front panel buttons, knobs and sliders are re-tasked to work as a controller for your computer DAW. This is not available on the Rack due to its lack of a suitable front panel.

However, the THRU PORT is defined as the PORT you can use to communicate with 1 external MIDI device when you connect a 5-pin MIDI IN and OUT cable to it. When you set MIDI IN/OUT = USB the 5-pin MIDI jacks are now available for other duties. Say you have a synthesizer keyboard connected to the 5-pin jacks. That keyboard would send its MIDI data “THRU” (without stopping) the Motif-Rack and arrive in your computer merged on PORT 1.
But data sent from the Computer DAW on the PORT number you designate as the “THRU PORT” (say you selected PORT 5) if in your DAW software you were to set a Track’s MIDI OUT = “Yamaha Motif-R-5” that track’s data would pass THRU the Motif-Rack (without stopping) and arrive at the 5-pin MIDI OUT jack of the Rack and go on to the MIDI IN of your connected external keyboard. Allowing tracks in your DAW to be targeted directly to that external device.

When the Motif Rack is used via USB, it can act as a MIDI INTERFACE for one external device connected to its 5-pin MIDI jacks. Hope that helps.

As to why you are getting a BUFFER FULL message is a matter of how you are routing signal to the Motif-Rack (there are no details concerning any of our connections so we can only guess but if you follow your signal flow you will find it.) For example, no mention of a computer in your post at all. Is one being used?

If yes, then start your search for an answer in your connections.

If no, then start your search by seeing if you can capture what the keyboard is sending out. Use a utility like MIDI-OX to see if you can see what messages are being sent - then you can either block them or have the Rack ignore them.

Either way you have not provided enough details. Let us know.
Welcome to the forums!