Flowchart Programming: A Natural Language for Control 961651
Control system programming is the task of describing the complex interactions among the various parts of a machine (or machines). There are many languages used for control system programming today. Among them all, one language stands out as being particularly well suited to the task. This language is Flowchart Programming.
A typical manufacturing machine has many activities happening at the same time. This parallelism is good because it reduces machine cycle time. Within each parallel activity, however, there is usually a set sequence of actions which must happen in the proper order.
In order to easily describe the desired behavior of such a machine, the control language must be able to express both parallel activity and serial activity. Flowchart programming can do this. Parallel activities are expressed by describing them in separate flowcharts. Serial activities are expressed as the machine executes through the “flow” of the desired actions.
This paper examines several aspects of the Flowchart language:
The programmers model in a Flowchart environment.
The characteristics of Flowchart programming which makes it good for control systems.
The types of control problems for which Flowchart programming is particularly well suited.
A comparison to other popular control system languages: Relay Ladder Logic (RLL) and Sequential Function Chart (SFC), in particular.