machine_var_(name)

MPF Event

Posted when a machine variable is added or changes value. (Machine variables are like player variables, except they’re maintained machine-wide instead of per-player or per-game.)

Keyword arguments

(See the Conditional Events guide for details for how to create entries in your config file that only respond to certain combinations of the arguments below.)

change
If the machine variable just changed, this will be the amount of the change. If it’s not possible to determine a numeric change (for example, if this machine variable is a list), then this change value will be set to the boolean True.
prev_value
The previous value of this machine variable, e.g. what it was before the current value.
value
The new value of this machine variable.