Optimistic data retrieval in a process control environment

1. A historian device for use with a client device for displaying statistical data in a process control environment, the historian device comprising:

a historian memory storage device and a historian processor including a counter, said historian memory storage device storing statistical data and storing processor-executable instructions for execution by the historian processor for implementing a historian connection module and a historian server module, said processor-executable instructions configured for, when executed by the historian processor:

incrementing by the counter, a count value at a rate at which products pass through the process element;

rolling over the count value to zero by the counter when the count value reaches a rollover value R after which the counter rolls the count value over to 0 and continues incrementing;

receiving by an historian device connected to the counter, count value data points periodically;

setting, in the historian device, a deadband value D for distinguishing among rollovers, resets, and/or reversals;

querying by a client device from the historian device, an amount of products passed through the process element for a timeframe;

selecting by the historian device, a set of count value data points received within the queried timeframe; and

determining by the historian device, based on the selected data points, an amount of products passed through the process element;

wherein the historian processor returns at the calculated value of the amount of products passed through the process element to the client device.

2. The device of claim 1 wherein the determining processor-executable instructions are configured for:

determining a reset has occurred if a first data point is greater than a following data point and the first data point is less than R*(1−D/100) and the following data point is less than R*D/100, and determining the amount of products passed through the process element based on the determined reset;

determining a reversal has occurred if the first data point is greater than the following data point and the difference between the first data point and the following data point is less than R*D/100, and determining the amount of products passed through the process element based on the determined reversal; and

determining a rollover has occurred if the first data point is greater than the following data point and it has not been determined that reset has occurred between the first and following data points and it has not been determined that a reversal has occurred between the first and following data points, and determining the amount of products passed through the process element based on the determined rollover.

3. The device of claim 2 wherein the determining processor-executable instructions are configured for at least one of the following:

if it has been determined that a rollover has occurred, the amount of products is increased by the rollover value R;

if it has been determined that a reset has occurred, the amount of products is increased by the value of the first data point;

if it has been determined that a reversal has occurred, the amount of products is decreased by the difference between the first data point and the following data point.

4. The device of claim 2 wherein the determining processor-executable instructions are configured for returning the calculated value of the amount of products passed through the process element to the client device.

5. The device of claim 2 wherein the determining processor-executable instructions are configured for the deadband value D is set as a percentage of a rollover value of the counter.

6. The device of claim 1 wherein the historian device receives a query for a result over a timeframe from the client device connected to the historian device, and wherein the historian device selects data points within the timeframe; and wherein the determining processor-executable instructions are configured for:

identifying in the historian device, data points as having a ‘GOOD’ quality, a ‘BAD’ quality, or a ‘DOUBTFUL’ quality;

setting in the historian device, one of the following quality rule modes:

a ‘GOOD’ quality rule mode wherein the historian device includes in the retrieval calculations data points with a ‘GOOD’ quality and a ‘BAD’ quality, wherein data points with a ‘DOUBTFUL’ quality will not be included in a calculation;

an ‘EXTENDED’ quality rule mode wherein the historian device includes in the retrieval calculations data points with both a ‘GOOD’ quality, a ‘BAD’ quality, and a ‘DOUBTFUL’ quality; and

an ‘OPTIMISTIC’ quality rule mode wherein the historian device includes in the retrieval calculations data points with both a ‘GOOD’ quality and a ‘DOUBTFUL’ quality except that data points with a ‘BAD’ quality will not be included in a calculation; and

wherein the determined amount of products by the historian device is based on the included data points; and

wherein the historian device returns the determined amount of products to the client device.

7. The device of claim 6 wherein the historian device sets at an ‘OPTIMISTIC’ quality rule mode wherein the historian device includes in its retrieval calculations data points except a “BAD” quality data point and wherein the determining processor-executable instructions are configured for at least one of the following:

if a “BAD” quality data point is encountered, then a last known ‘GOOD’ quality data point or a last known ‘DOUBTFUL’ quality data point is used as if the “BAD” quality data point never occurred;

if a “BAD” quality data point is encountered, then a last known ‘GOOD’ quality data point or a last known ‘DOUBTFUL’ quality data point is used as if the “BAD” quality data point never occurred; wherein if a particular data point is a “BAD” quality data point and if there are no points prior to the start of the query, then 0.0 will be used as a starting base value for the particular “BAD” quality data point; and

if a “BAD” quality data point is encountered, then a last known ‘GOOD’ quality data point or a last known ‘DOUBTFUL’ quality data point is used as if the “BAD” quality data point never occurred; wherein if a particular data point is a “BAD” quality data point and if there are no points prior to the start of the query, then 0.0 will be used as a starting base value for the particular “BAD” quality data point, and then the value change for the cycle is calculated from the first actual data point in the cycle, rather than 0.0.