Editing Very Simple Control Protocol (section)

==Decision matrix==
[[Image:VSCP_Class_Event_mask_filter.png|350px|right|VSCP class/event mask & filter]]
When events are received by a node the node needs to determine if it needs to execute a task based on that event. This is done by evaluating the ''decision matrix'' or DM in short. The DM matrix is made of a number of IF ... THEN ... conditions. Each such IF/THEN condition is called a ''line'' and multiple lines make up the decision matrix.

The Class and Type of the incoming message is always evaluated by a DM line. Evaluating Class & Type is done by passing the Class/Type through a mask first and then comparing with a filter.
This method allows multiple class/Types to trigger a valid condition for 1 line of the DM. The other conditions for the DM line (SenderGUID, Zone, Subzone) are optionally evaluated.
If the DM line is valid then the ''ACTION'' is executed. Together with the ''ACTION'' there is an ''ACTION parameters''. An example ACTION would be: ''turn-on relay 6'' with ''6'' being the ''action parameter''.
Exactly which ACTIONs are possible by the receiving node is determined by the design of the node itself. It is up to the firmware developer to define which actions can be executed. By then documenting the possible action in the MDF file (see later) the configuration SW will know how to select this action.
The DM can be modified by setting the appropriate node configuration registers. A convenient way to do this is using the VSCPWorks configuration SW.