Nodes

Synth Node

Analog3 synth image consists of nodes. A node is a component that has metadata and sub-node. Every node is accessible from a3 clients and a node can map to physical component.

Here is an example model description of a MIDI Gateway module:

{
  "node_type": "Module",
  "node_name": "MIDI Gateway",
  "component_number": 0,
  "model_name": "a3.midigw.000",
  "model_id": 1,
  "channel": "can",
  "child_nodes": [{
    "node_type": "Switch",
    "node_name": "MIDI Channel",
    "component_number": 1,
    "options": [
      "1", "2", "3", "4", "5", "6", "7", "8",
      "9", "10", "11", "12", "13", "14", "15", "16"
    ],
    "initial_value": 0
  }, {
    "node_type": "Switch",
    "node_name": "Voices",
    "component_number": 2,
    "options": [
      "1", "2", "4"
    ],
    "initial_value": 0
  }, {
    "node_type": "Switch",
    "node_name": "Retrigger",
    "component_number": 3,
    "initial_value": 0
  }]
}

Node Types

There are several types of nodes as follows:

• Module
  A module is a unit of functionality. It is either a reflection of a physical module or software-generated image of a function. An instance of module has a unique instance ID that is used as an address in inter-module communication. For physical module, its CAN ID is used for the instance ID.
• Knob
  A knob is a parameter controller. It has one value and it is modifiable by external node.
• Switch
  Switch changes mode of functionality. In default, a switch has two options: on and off. Number of options can be increased by model definition. Each option has a name, so it can be used as a selector, too.
• Output

and so on

Node Attributes

Node Metadata

Following attributes are metadata commonly used for any types of nodes.

Property Name	Type	Model Parameter?	Description	Possible Values	Default
node_type	string	required	Type of the node.	Module, Knob, Switch	n/a
node_name	string	required	Name of the node.	any string	n/a
instance_id	uint16	no	ID of an instance. A single instance ID is shared by components in a module.	TBD (10 bit?)	given to top, child inherits top's
component_number	uint8	required	sub address under a module, component number of a module is always 0. The value must be unique in the module the node belongs to.	0 to 255	n/a
channel	enum	optional	Access channel to implementation	can, TBD	inherits parent's channel
initial_value	uint16	optional	Every node has zero or one value. This property sets the initial value.	0 to 65535	0
value	uint16	no

Module Specific Attributes

Property Name	Type	Model Parameter ?	Description	Possible Value	Default
model_name	string	required	Name of the model	any string	n/a
model_id	uint16	required	Unique identifier that distinguishes the model	0 to 65535	n/a

Knob Specific Attributes

Property Name	Type	Model Parameter ?	Description	Possible Value	Default
min_value	uint16	optional	minimum value	any	0
max_value	uint16	optional	maximum value	any	65535
offset	uint16	optional	value that represents '0'	any	0
scale	uint16	optional	number of value ticks that indicates '1'	any	1

Switch Specific Attributes

Property Name	Type	Model Parameter ?	Description	Possible Value	Default
switch_type	enum	required	Type of the switch	TOGGLE, MOMENTARY, ROTARY, SELECTOR	viewer automatically determines
options	string[]	optional	This attribute specifies number of options that the switch can choose and name of each option.	any array of strings	[ 'off', 'on' ]