Multi-node utilization of a single network variable input for computation of a single control variable at a sink node

An automation control system comprising:

• a source controller having a network variable output for providing an update value;
• a first sink controller having a network variable input for receiving the update value from the network variable output of the source controller, a function for operating on the update value and a local value, and also having a network variable output for providing an update value corresponding to the operation of the function;
• and
• a second sink controller having a network variable input coupled to the network variable output of the first sink controller whereby the second sink controller receives the update value corresponding to the output of the function of the first sink controller on a single network variable input.

A method for controlling a system having controllers comprising:

• providing an update value on a network variable output of a first controller;
• receiving the update value on the network variable input of a second controller;
• operating on the update value and a local value at the second controller;
• providing on a network variable output of the second controller an update value corresponding to the operation of the function;
• and
• receiving the update value on a network variable input of a third controller, the received update value corresponding to the operation of the function at the second controller whereby the receipt of the update value at the third controller corresponding to data at the first and second controllers occurs at a single network variable input.