INFO-SCAN involves many sources of control commands. These controls include a variety of application functions. Some of the application functions reside in remote field panels, while others reside in the processor. 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, INFO-SCAN includes control processing software. All control requests must be validated by this software before they are issued.

The control processing software checks for conflict between controllers. This process is known as contention resolution. All controllers, both programs and operators, are assigned control priorities for analog control and for each state to which they may order a device. 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. 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. Maintenance alarms can also be established when the runtime or number of starts exceeds preset limits.