ezeio2:scriptref:start

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ezeio2:scriptref:start [2019-09-02 20:51] – andrehezeio2:scriptref:start [2020-11-12 22:53] – johpar
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 ===== Script reference ===== ===== Script reference =====
-{{indexmenu_n>710}}+{{indexmenu_n>900}}
  
 === ezeio script programming - the PAWN language === === ezeio script programming - the PAWN language ===
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 Although the user script runs in a sandboxed runtime engine, the recommended programming pattern is similar to [[https://en.wikipedia.org/wiki/Cooperative_multitasking|cooperative multitasking]]. Although the user script runs in a sandboxed runtime engine, the recommended programming pattern is similar to [[https://en.wikipedia.org/wiki/Cooperative_multitasking|cooperative multitasking]].
  
-This means that you should avoid long-running loops, and instead make use of blocking calls or system callbacks provided in the function library. +This means that you should avoid long-running loops, and instead make use of system callbacks provided in the function library.
- +
-The following calls are blocking: +
- +
-| ''ModbusRead()'' | Read a register block from a Modbus RTU device | +
-| ''RS485WriteRead()'' | Write & Read to the Modbus port in 'raw' mode (not Modbus protocol) | +
-| ''ModbusWriteRead()'' | Write and read Modbus commands on the RTU port | +
-| ''SDICmd()'' | Send a SDI12 command and receive the response | +
-| ''ModbusTCP()'' | Send & Receive Modbus commands on the Ethernet port | +
-| ''sleep()'' | Suspend the script for a short time (process events immediately) | +
-| ''msSleep()'' | Suspend the script for a short time (not processing events - DEPRECIATED) | +
-| ''MBRTU_Read()'' | Read a register from a Modbus RTU device | +
-| ''MBRTU_Write()'' | Write to a register on a Modbus RTU device | +
-| ''MBTCP_Read()'' | Read a register from a Modbus TCP device | +
-| ''MBTCP_Write()'' | Write to a register on a ModbusTCP device | +
-| ''SunSpecIP_Base()'' | Find the base address for a SunSpec/TCP device | +
-| ''SunSpecIP_Ofs()'' | Find the offset for a SunSpec/TCP device | +
  
 The following system callback functions are defined: The following system callback functions are defined:
  
 | ''@Tick'' | Called at a regular interval, set by SetTickInterval() | | ''@Tick'' | Called at a regular interval, set by SetTickInterval() |
-| ''@Timer'' | Called when one of the four millisecond timers expire, see SetTimer() |+| ''@Timer'' | Called when one of the millisecond timers expire, see SetTimer() |
 | ''@Action'' | Called when an action is triggered due to an alarm event | | ''@Action'' | Called when an action is triggered due to an alarm event |
 | ''@Key'' | Called when a button is pressed on a connected terminal device | | ''@Key'' | Called when a button is pressed on a connected terminal device |
 | ''@Scan'' | Called when a code is received from a scanner device | | ''@Scan'' | Called when a code is received from a scanner device |
-| ''@J1939'' | Called when a J1939 packet is received | 
  
 +=== State machines ===
 +
 +A common programming pattern in control applications is to use state machines. PAWN and the ezeio implements strong support for state machines. The following is a typical pattern showing the startup sequence of an engine. Note that there are three @Tick handlers; one for each state. Also note the "entry" and "exit" functions. For more detail, refer to the PAWN language guide.
 +
 +<code javascript>
 +
 +  new count = 0;
 +
 +  main()
 +  {
 +    SetTickInterval(100);   // set tick interval to 100ms (0.1s)
 +    state WAITING;          // start in the waiting mode
 +  }
 +  
 +  @Tick(uptime) <WAITING>
 +  {
 +     if( GetField(1) < 100 )  // condition to start up the process
 +        state IGNITION;
 +  }
 +  
 +// ***** the IGNITION state
 +
 +  entry() <IGNITION>
 +  {
 +     SetOutput(1, 100);       // Turn on the ignition switch
 +     count = 0;
 +  }
 +  
 +  @Tick(uptime) <IGNITION>
 +  {
 +     if( GetField(2) > 100 )  // Did the engine start?
 +        state RUNNING;        // yes - we're running
 +
 +     if(count++ > 50)
 +        state WAITING;        // didn't start in 5s? Give up and go back to waiting.
 +  }
 +  
 +  exit() <IGNITION>
 +  {
 +     SetOutput(1, 0);         // Turn the ignition switch off
 +  }
 +  
 +// ***** the RUNNING state
 +
 +  @Tick(uptime) <RUNNING>
 +  {
 +     if( GetField(2) < 100 )  // Check if the engine stopped
 +        state WAITING;        // ..go back to waiting
 +  }
 +  
 +</code>
  
  • ezeio2/scriptref/start.txt
  • Last modified: 2024-03-01 17:24
  • by andreh