Input/output (I/O) scanner for a control system with peer determination

A method comprising the steps of:

• providing a first device on a first node of a communications network, the first device configured to connect to and scan I/O devices;
• providing a second device on a second node of the communications network, the second device configured to connect to and scan the I/O devices;
• assigning a first address to a the first node and a second address to a the second node, wherein the first address is characteristic of a primary mode of operation;
• initiating from the first node a first communications command in a peer protocol format addressed to the second node;
• initiating from the second node a second communications command in the peer protocol format addressed to the first node;
• identifying the second device on the second node as a peer device within the first device on the first node responsive to receiving the second communications command at the first node;
• identifying the first device on the first node as a peer device within the second device on the second node responsive to receiving the first communications command at the second node;
• wherein the peer device is a programmable logic controller (PLC) device;
• scanning the I/O devices by the first device on the first node;
• determining that the first node is inoperable;
• initiating at the second node an exchange of the first address and the second address responsive to determining that the first node is inoperable;
• resetting a connection between the first device and the I/O devices responsive to determining that the first node is inoperable;
• and
• assigning the first address to the second node and the second address to the first node responsive to initiating the exchange.