Relay

MIDI Solutions Relay

The MIDI Solutions Relay contains a relay that can be programmed to open or close in response to MIDI events (for eight relays in a single rack space unit, see the MIDI Solutions R8).

Event types are programmable and include:

1. Note:

The Relay can be programmed to respond to Note messages of programmable Note number and MIDI channel (a single MIDI channel or all 16 MIDI channels). The Relay can accept a combined total of 10 Note or Control Change settings.

The Relay can respond to Note messages in four modes:
1.
CLOSE for Note-ons, OPEN for Note-offs 
2.
OPEN for Note-ons, CLOSE for Note-offs 
3.
CLOSE for both Note-ons and Note-offs 
4.
OPEN for both Note-ons and Note-offs
The first two modes allow the Relay to open or close in response to Notes being turned on or off. Combining the last two modes allows the Relay to close on receiving some Notes and open on receiving others.

2. Control Change:

The Relay can be programmed to respond to Control Change messages of programmable Control Change number and MIDI channel (a single MIDI channel or all 16 MIDI channels). The Relay can accept a combined total of 10 Note or Control Change settings.

The Relay can respond to Control Change messages in four modes:
1.
CLOSE for values 64 and higher, OPEN for values below 
2.
OPEN for values 64 and higher, CLOSE for values below 
3.
CLOSE for all values 
4.
OPEN for all values
The first two modes allow the Relay to open or close in response to Control Change messages being turned on or off. Combining the last two modes allows the Relay to close on receiving some Control Change messages and open on receiving others.

3. Program Change:

The Relay can be programmed to respond to Program Change numbers 0 to 127, on any MIDI channel (a single MIDI channel or all 16 MIDI channels). The Relay can be programmed to OPEN or CLOSE on receiving each Program Change number.

4. System Exclusive:

The Relay can be programmed to CLOSE when a System Exclusive message is received, and/or OPEN when another System Exclusive message is received.

Since MIDI Machine Control messages are a type of System Exclusive message, the Relay can be set up to respond to messages such as transport commands. For example the Relay could be programmed to open and close in response to MIDI Machine Control Play and Stop messages.

The maximum length of each System Exclusive message is 20 bytes.

 

A fast read relay is used for a response time of less than 2ms. Relay contact is rated at 500 mA. Contacts are made available via connection at the tip and sleeve of a 1/4" mono phone jack. When switching inductive loads be aware of precautions that must be taken to avoid back EMF problems.

The Relay is programmed by sending it MIDI System Exclusive messages. This can be done easily with the Processors Programming Tools software. Once programmed, its settings are retained even after power is removed. The Relay can be reprogrammed with new settings as often as needed.

The Relay is MIDI-powered, and requires no batteries or power supply to operate with most MIDI products. A MIDI indicator LED lights up when the product is powered and flashes when MIDI data passes through it.

weight: 4.3 oz.
dimensions: 4-3/16" x 2-3/16" x 1-3/32"

 

 

Diagram

 

Application Example

The MIDI Solutions Relay contains a contact closure that can be programmed to open and close in response to a variety of MIDI messages. The R8 is essentially eight MIDI Solutions Relays in a single rack space unit.

Probably the easiest way to use the MIDI Solutions Relay is to set it up to respond to a Note or Controller message. The relay can then be activated by an operation as simple as hitting a key on the keyboard or depressing a footswitch. If the key or footswitch movements are recorded into a sequencer, the sequence can later be replayed and the relay will respond in exactly the same way it was recorded.

The Relay can also be programmed to respond to Program Change messages. This can be useful for controlling non-MIDI devices while cycling through program changes during a live performance. For example, consider a setup that uses a MIDI pedal board to send program changes to an effects unit. Add to this a guitar amp that allows switching from clean to dirty via a 1/4" footswitch input, but not via MIDI. The relay can be connected directly to the footswitch input of the guitar amp to control it as program changes occur, placing this non-MIDI device under MIDI control. With both the effects unit and the guitar amp responding to program change messages sent by the MIDI pedal board, it is now possible to create customized effects that combine both of these products.

Another type of message that the Relay can be programmed to respond to is System Exclusive, including MIDI Show Control and MIDI Machine Control messages such as transport commands from devices like digital audio recorders or sequencers. For example you could set up the relay to close in response to a MIDI Machine Control Play message, and open in response to a MIDI Machine Control Stop message. The relay output could then be used to control an external device, such as an indicator light.