Multi-rate optimized connection between industrial control scanner and industrial controller

A method of operating an industrial control system comprising the steps of:

• (a) connecting a plurality of I/O modules to a scanner, the I/O modules operable to interface with a process to exchange I/O data with the process;
• (b) exchanging I/O data between the I/O modules and the scanner to create in the scanner an optimized connection packet including the I/O data for each I/O module arranged in an unformatted data block;
• (c) opening a first connection between the scanner and an industrial controller to exchange the optimized connection packet with the industrial controller in a first connected message at a first rate at first times, wherein the first connected message pre-allocates network bandwidth and buffer space;
• (d) storing the I/O data contained within the optimized connection packet in a buffer;
• (e) opening a second connection between the scanner and the industrial controller to exchange a subset of the optimized connection packet with the industrial controller in a second connected message at a second rate at second times interleaved with the first times;
• and
• (f) storing the I/O data contained within the subset of the optimized connection packet in the same locations of the buffer as the I/O data from the first connected message,
• wherein the I/O data contained within the subset of the optimized connection packet is delivered more frequently than I/O data of the optimized connection packet other than the subset of the optimized connection packet.

A computer program stored in a computer memory for operating an industrial control system having a plurality of I/O modules connected to a scanner, the I/O modules operable to interface with a process to exchange I/O data with the process;

• the scanner operable to collect I/O data exchanged between the I/O modules and the scanner into an optimized connection packet including the I/O data for each I/O module arranged in an unformatted data block, the computer program executing to:
• (i) open a first connection between the scanner and an industrial controller to exchange the optimized connection packet with the industrial controller in a first connected message at a first rate at first times, wherein the first connected message pre-allocates network bandwidth and buffer space;
• (ii) store the I/O data contained within the optimized connection packet in a buffer;
• (iii) open a second connection between the scanner and the industrial controller to exchange a subset of the optimized connection packet with the industrial controller in a second connected message at a second rate at second times interleaved with the first times;
• and
• (iv) store the I/O data contained within the subset of the optimized connection packet in the same locations of the buffer as the I/O data from the first connected message,
• wherein the I/O data contained within the subset of the optimized connection packet is delivered more frequently than I/O data of the optimized connection packet other than the subset of the optimized connection packet.