The 225e MIDI Decoder / Preset Manager translates incoming MIDI messages into analog voltages and pulses, which appear on three kinds of busses for subsequent distribution to 200e-series modules.
Four internal busses route signals to those 200e series modules that respond directly to MIDI messages. Each bus conveys messages appropriate to the destination module: Pulses are routed to a 281e, velocities to a 292e, and pitches are directed to up to four 259e or 261e modules.
Four note-message busses decode the incoming MIDI signal and convert it into voltages, accessible from the 225e front panel, that represent pitches, velocities, and pulses with sustain information.
Six Controller busses are provided, each supporting two independent controllers. Control information is output as standard (10V range) control voltages.
Controller output bus P(b) is a dedicated MIDI Clock output.
Any number of busses can be assigned to a single MIDI channel. Note messages so assigned can be directed to respond polyphonically.
Built into the 225e, but independent of the MIDI Decoder, is the Preset Manager, which is used to store and recall the settings of nearly all system variables.
The 225e can also poll and display the current firmware version of any 200e-series module in a system and, in conjunction with a Macintosh computer running OSX 10.5 or above, can be used to download / update 200e systems with the latest firmware.