Control Modules

A control module can consist of a collection of sensors, actuators, other control modules, and associated processing equipment that is operated as a single entity.

A control module is where direct connections to sensors and actuators are made in the factory. Most of the data connections you make to resources are made to control modules. Control modules may be given commands such as start and stop or “set speed”, or can provide information, such as temperature, speed, or alarm information.

A control module can also be made up of other control modules. For example, the heating system in a wave soldering machine may consist of an upper heating coil and a lower heating coil, along with a common temperature output of the solder. You may want to model this as a control module, and then model each heating coil independently as control modules within it. This allows you to control and measure both as a group, or to individually control or monitor them.

Where equipment modules are controlled procedurally through defined sequences or recipes, control modules are driven to a certain state; for example, a temperature element that has a temperature control. Setting the temperature drives the heating element until the requested temperature is reached. Even if the control module internally has complex logic to attain the state, the exposed interface to the world is simple – set a value, read a value.

A control module can be a terminating resource; that is, the last resource in a hierarchy.

The following information describes the hierarchy of this resource:

Required:no; optional
Contained by:Equipment module; Control module.
Can Contain:one or more Control modules.