Patent ID: 6662247
Filing Date: 2003-12-09
Classification: G05B

Abstract:
An industrial control I/O system for use with I/O modules attachable to a backplane, the I/O modules transmitting real time electrical values to an industrial process via outputs of the I/O module determined by an I/O data unit, the I/O system comprising:a backplane having connector slots receiving I/O modules and providing data conductors and slot address signals specific to a connector slot; an adapter connected to the backplane and executing a stored program to: (a) receive an I/O data unit for transmission over the backplane to an I/O module; (b) receive a low priority data unit for transmission over the backplane to the I/O module; (c) form a transmission data block of predetermined length incorporating the entire I/O data unit and only a portion of the low priority data unit smaller than the I/O data unit; (d) sequentially enable the slot address signals to each connector slot at a predetermined scan rate; (e) when the slot address signal to a connector slot holding the I/O module is enabled, transmit the transmission data block to an I/O module in the connector slot; and (f) repeat step (a) and (c)-(e) where at step (a) a new I/O data unit is received and wherein at step (c) the transmission data block holds the new I/O data unit and a different portion of the low priority data unit, the repetition proceeding until the complete low priority data unit has been incorporated into different data block and transmitted to the I/O module in the connector slot; whereby low priority data of arbitrary size can be integrated into a fixed scan based backplane without compromising the delivery of real-time I/O data.