InfoScan provides for many sources of control commands, including many application functions. Some originate from remote controllers in panels, while others may be operator initiated. If each of these controllers were allowed to issue requests without considering what the others were doing, chaos and quite possibly, equipment damage would result. To prevent this, InfoScan includes control processing application schemes to validate controls before they are issued.
This process is known as contention resolution. All controllers, whether process, programs, or operators, are assigned control priorities. When a control request is issued, its priority must be equal to or higher than that of the previous controller unless the previous controller reset the contention mechanism, in which case all priorities are accepted.
The control processing software also handles several bookkeeping functions. In addition to min/max on/off time, it maintains the runtime and number of starts as well as time of last start and last state change for each device for use in reports and logs.