Systems and methods for providing status data to a requesting device are
disclosed. A request for status data is transmitted from a requesting
device to a providing device. The request includes prior values of
variables stored at the requesting device. At the providing device, the
transmitted prior values are compared with current values of the
variables stored at the providing device. Changed variables, which
comprise variables for which the current value is different from the
prior value, are identified. A variable map is formulated that identifies
the changed variables. Current values for the changed variables and
variable map are organized into a pre-defined format to form status data.
The status data is transmitted to the requesting device.