(only text sections, graphics in preparation)Index
1. Function of the MMR4/4
MMR4/4 is a MIDI matrix with merge function. It is equipped with 4 MIDI inputs and 4 MIDI outputs. Inputs and outputs can be assigned in any combination. If an output is assigned to more than one input the regarding inputs are merged.
The routing is set with 8 buttons and 8 LEDs at the front panel which are assigned to the 4 MIDI inputs and outputs. The LEDs display the input/output configuration which can be changed very easy with the corresponding buttons. During normal operation (monitor mode) the LEDs display the MIDI activities on the inputs and outputs. A panic button is available transmitting "all notes off" on all channels and outputs if activatet.
The MMR4/4 MIDI Matrix
MMR4/4 is available in a light grey aluminium standard case (dimensions: 200 x 100 x 42 mm) or in the 19" version with 1 HU (same case as standard version but equipped with a large light grey 19" front panel).
Connect the MIDI In sockets at the rear panel of the MMR4/4 via suitable cables to the MIDI Out sockets of your MIDI transmitters (e.g. Master Keyboard, Synthesizer, Sequenzer, Fader Box). Connect the MIDI Out sockets at the rear panel of the MMR4/4 via suitable cables to the MIDI In sockets of your MIDI receivers (e.g. Expander, Sampler, Synthesizer, Sequenzer, MIDI-CV-Interface). Only the required MIDI inputs and outputs are connected. Not required sockets remain open.
MMR4/4 does not have a built-in power supply. Instead it uses a plug-in type external power supply (AC adapter). The power supply PS1 for 220...240V AC mains voltages is included with the MMR4/4. For other mains voltages the power supply must be purchased by the customer in his country. The AC adapter used has to be in accordance with the following specifications. It must be able to deliver 7...9 V DC unstabilized or stabilized voltage, as well as a minimum current of 500 mA. The polarity of the low voltage plug (2.1 or 2.5 mm diameter) connected to the MMR4/4 must be the following: pin = +7...9V and ring = GND. If the polarity is incorrect, MMR4/4 will not function. However, there is no danger of damage to the circuitry since it is protected by a diode. If the MMR4/4 is used in Germany the external power supply should be VDE approved like the PS1.
The MMR4/4 is turned on by plugging the AC adapter into a wall outlet and connecting it to the appropriate jack on the back of the MMR4/4. There is no separate ON/OFF switch. After turning the MMR4/4 on the LED labeled "power" must light. Otherwise the power supply used is faulty (wrong voltage, wrong polarity, insufficient current or defective).
3.1. MONITOR MODE
When turning on the MMR4/4 the last matrix configuration 1 (Preset 1) is called up and the MMR4/4 enters the MONITOR MODE. In this mode the 8 LEDs labeled "DISPLAY ROUTING" display the MIDI activities on the MIDI inputs and outputs. The 4 leftmost LEDs relate to the MIDI inputs, the 4 rightmost to the outputs.
3.2. ROUTING MODE
To modify the matrix configuration you have to enter the ROUTING MODE by pressing one of the buttons labeled "SET ROUTING". The LED corresponding to the pressed button flashes. E.g. if the button MIDI IN 2 was pressed the LED "MIDI IN 2" will flash. You may enter the ROUTING MODE from the "input view" or "output view". In the first case one of the 4 inputs is selected and the outputs are routed to the selected input. In the second case one of the 4 outputs is selected and the inputs are routed to the selected output. Which type of assignment you choose depends upon whether you prefer to see the MIDI matrix from the input or output view. The two assign types are different presentations of the same matrix configuration.
If one of the "MIDI IN" buttons was pressed the corresponding MIDI In LED flashes and the 4 "MIDI OUT" buttons are used to assign the outputs to the selected input. Turning on/off the outputs happens by repeated pressing of the regarding output button. If an output is routed to the selected input the corresponding "MIDI OUT" LED lights up. If an output is not routed to the selected input the corresponding "MIDI OUT" LED remains dark. To reenter the MONITOR MODE the "MIDI IN" button of the selected input has to be pressed again. The routing display disappears and the 8 LEDs display again the MIDI activities.
If one of the "MIDI OUT" buttons was pressed the corresponding MIDI Out LED flashes and the 4 "MIDI IN" buttons are used to assign the inputs to the selected output. Turning on/off the inputs happens by repeated pressing of the regarding input button. If an input is routed to the selected output the corresponding "MIDI IN" LED lights up. If an input is not routed to the selected output the corresponding "MIDI IN" LED remains dark. To reenter the MONITOR MODE the "MIDI OUT" button of the selected output has to be pressed again. The routing display disappears and the 8 LEDs display again the MIDI activities.
In order to display or change the complete matrix configuration you have to select the ROUTING MODE for all inputs or all outputs one after another.
MMR4/4 has 4 non volatile memories (Presets) to store 4 different matrix configurations. To select one of the Presets you have to press the button "MIDI IN 1" and keep it pressed until the LED "MIDI IN 1" is flashing slowly. Now you can choose one of the 4 Presets with one of the 4 "MIDI OUT" buttons. To return to the normal monitor or routing mode you have to press the button "MIDI IN 1" again.
Once you have selected a Preset all routing changes are stored into the memory of the Preset selected. When turning on the MMR4/4 always Preset 1 is called up. So you should store the most important routing to Preset 1.
You have to pay attention that no MIDI events occur at the MIDI inputs during the rearrangement of the MIDI matrix, i.e. while changig the matrix configuration in the ROUTING MODE or while calling up another Preset. Otherwise hanging notes or other undesired effects may happen e.g. as the note off event corresponding to a preceding note on event is missing. In this case the PANIC button may help.
Near the "POWER" LED you may find a button labeled "PANIC". Whenever this button is pressed "all notes off" events on all 16 MIDI channels on all 4 outputs are sent. The panic button is used to get rid of hanging notes provided that the MIDI receivers used recognize the "all notes off" command.
4. Additional Comments
To initialize the MMR4/4 the button 8/MIDI OUT 4 has to be pressed while turning the unit on. The MMR4/4 then is set to the following basic configuration: Input 1 = Output 1, Input 2 = Output 2, Input 3 = Output 3, Input 4 = Output 4. While the unit is initialized all 8 LEDs are flashing.
MMR4/4 processes all types of MIDI events but there are restrictions for some events and high transmission rates when data are subject to merge. If the merge function of the MMR4/4 is used the following hints should be noticed. Merging happens whenever two or more inputs are routet to one output.
Of course the MMR4/4 is not able to increase the MIDI transmission rate. The sum of the incoming MIDI events to be merged must not exceed the maximum MIDI transmission rate. Otherwise data loss may be the result. This is not a problem of the MMR4/4 but happens whenever MIDI data will be merged. That is why merging has to be limited to only partly occupied MIDI lines. For example merging of a nearly fully occupied sequencer output with the output of a MIDI fader box generating a high rate of controller events will not work.
You should merge inputs only if it is really necessary. Each needless merge reduces the performance of the other in/outputs. E.g. a matrix configuration where all 4 inputs are routet to all 4 outputs does not make much sense in practice. Turn off all combinations/crosspoints not used. This improves the performance of the data transmission.
There may also occur problems if MIDI realtime events are merged. Only one MIDI realtime master is allowed in a MIDI system. So if realtime events (clock, start, stop, continue) appear on two ore more inputs the MMR4/4 has to decide which input is passed thru. MMR4/4 solves the problem by passing only the realtime events of those input on where they arrived first. Of course the better solution is to pay attention that this case never takes place as two MIDI realtime masters doesnt make much sense.
Merging of System Exclusive events is in MIDI not possible. That is why Sysex data are allowed to arrive only at one MIDI input at a time. If system exclusive data are to be transmitted the other inputs are locked during the sysex transmission. The MIDI specifications prescribes that Sysex data must be sent in one package and are not allowed to be interrupted by other MIDI events like note on/off, control change, program change or others. If there are only short Sysex data packages the data on the other inputs will be stored and sent after the termination of the Sysex transmission.
Long Sysex transmissions like Dumps should be routet only to one output because of the multiplication of the data amount. Otherwise there may occur a MIDI overflow within the MMR4/4.
When working out the MIDI data at the inputs and outputs there are some preferential treatments. The priorities for the inputs and outputs are the following:
MIDI inputs: 1-2-3-4. Input 1 has the highest priority and may be used for high data rates. Input 4 is suitable only for low data rates.
MIDI outputs: 1-4-2-3. Output has the highest priority and may be used for high data rates. Output 3 is suitable only for lower data rates.
Running Status on/off
MIDI Running Status means that MIDI status bytes are sent only if the status changes (e.g. from note on to program change). Otherwise only data bytes without status byte are sent. If Running Status is on this may reduce the amount of bytes to be sent via MIDI out. If you are familiar with the MIDI Running Status mode you may determine for each output whether the Running Status is on or off (default is on for all outputs).
To set/reset the Running Status you have to press the button "MIDI IN 2" and keep it pressed until the LED "MIDI IN 2" is flashing slowly. Now you can set or reset the Running Status for each of the 4 MIDI outputs with the 4 "MIDI OUT" buttons. If the corresponding "MIDI OUT" LED is on the Running Status is activated for this output. To return to the normal monitor or routing mode you have to press the button "MIDI IN 2" again.
The Running Status on/off function is valid only if the MIDI data of the corresponding output is merged from two or more inputs. If the incoming data are only transmitted without merging to an output the data remain unchanged without Running Status modification.