System for communicating diagnostic data in an industrial control system

A system for communicating non-I/O data between components of an industrial control system (ICS), the components including control or automation devices and a programmable logic controller, the system comprising:

• a) a first translator included in a first one of the components, for providing as a virtual I/O message frame at least some of the non-I/O data, encapsulated in an I/O message frame and bearing a message type identifier pre-determined to correspond to the encapsulated non-I/O data;
• b) a second translator included in a second one of the components, responsive to the virtual I/O message frame, for extracting the encapsulated non-I/O data from the virtual I/O message frame based on the message type identifier pre-determined to correspond to the non-I/O data.

A method for use by components of an industrial control system (ICS) in communicating non-I/O data provided by the components of the ICS, the ICS having components including control or automation devices and a programmable logic controller, the components communicating with each other via a field bus, the method comprising the steps of:

• a) transmitting over the field bus the non-I/O data and a message type identifier formatted as a formatted I/O data signal, the message type identifier for distinguishing the formatted non-I/O data signal from a formatted I/O data signal;
• and
• b) receiving over the field bus the formatted non-I/O data signal and determining that the formatted non-I/O data signal includes non-I/O data by use of the message type identifier.