February 18, 2015 - SoftPLC adds Statechart Programming to their PACs. Statechart Programming provides a structured way to apply C++ to control applications, while at the same time sharing both measured and calculated variables with HMI/SCADA systems via standard industrial protocols. Finite State Machines (FSM) are known to be easy to troubleshoot because their "problem search space" is small and focused. The only control expressions pertinent to troubleshooting a problem are those used in the current state, so knowing the current state brings the troubleshooter immediately into a reduced problem region of concern. The current state is advertised both through a datatable variable and optionally the state transition monitor in debug mode.
Likewise, execution is extremely fast, since again, the only control expressions being executed are those residing in the current state. Thus it is possible to be concurrently executing many state machines concurrently even on moderately powered CPUs.
Features include:
- State transition monitor for debugging.
- State dwell timer.
- No limit to the number of FSMs
- Variables can be either private to a portion of code or shared in the PAC datatable.
- Shared variables can be bool, int16_t, float32_t, array of int16_t, array of float32_t,
- and structures.
Applicable to every state machine and every state, tells how long any FSM has been in its current state.
Private variables can be any C++ type.
