Concepts

Control Unit

A controller and the collection of I/O modules connect to it are referred to as a logical control unit (more information).

Named Variables

Names given to the inputs and outputs of the smart I/O modules are called named variables (more information).

Script

The script or programming script is a set of instructions interpreted and executed by the controllers. These instructions, along with the concept of named variables (see above), form the conceptual basis of automating the control tasks. The script may be written in simple ASCII text form or be obtained from a code generator template. If written in ASCII text, the script must conform to the iNetGrow scripting language syntax.

Parameter

A parameter is a variable saved in non-volatile memory. That is, parameters are saved even if the power to the controller is turned off. The script may use parameters as ordinary variables. Parameters are useful to store set points or program modes. Parameters are accessible through iNetGrowX function calls. Refer to the section “Programming” for more information about the use of parameters.

System Variable

A system variable is a predefined variable than can be used in the script. System variables start with the underscore (‘_’’) character. For instance, “_second” is current seconds kept by the clock of the controller. Refer to the section “Programming” for more information about the use of system variables.

Process

In the iNetGrow system, the process is the collection of activities and relationships under the control of the script (see above). Processes are specific to the controller executing the script. Processes include automated tasks and manual triggers. Automated tasks are associated with script instructions that set the values of the outputs as a function of inputs, outputs, and parameters. Manual triggers are instructions that set the outputs as a function of outputs and parameters. See the sections “Automated Tasks” and “Manual Triggers” under the heading “Programming.”