ezeio2:scriptref:start

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ezeio2:scriptref:start [2019-09-02 21:29] – andrehezeio2:scriptref:start [2024-03-01 17:24] (current) – andreh
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 ===== Script reference ===== ===== Script reference =====
-{{indexmenu_n>710}}+{{indexmenu_n>1000}}
  
 === ezeio script programming - the PAWN language === === ezeio script programming - the PAWN language ===
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 We strongly recommend reading the following documents to get introduced to the PAWN language: We strongly recommend reading the following documents to get introduced to the PAWN language:
  
-[[https://github.com/compuphase/pawn/raw/master/doc/Pawn_Getting_Started.pdf|Introduction to PAWN]]+[[https://doc.eze.io/_media/ezeio2/pawn_getting_started.pdf|Introduction to PAWN]]
  
-[[https://github.com/compuphase/pawn/raw/master/doc/Pawn_Language_Guide.pdf|PAWN language guide]]+[[https://doc.eze.io/_media/ezeio2/pawn_language_guide.pdf|PAWN language guide]]
  
  
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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 and are allowed in 'superloops': +
- +
-| ''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:
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 | ''@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 |+ 
 +=== Some examples === 
 + 
 +The program below will print out "Hello" on the debug console. 
 + 
 +<code javascript> 
 +main() 
 +{ 
 +    PDebug("Hello"); 
 +} 
 +</code> 
 + 
 +The following example adds the values of field 1 and field 2 together, and writes the result to field 3. 
 + 
 +<code javascript> 
 +// This example adds the value of field 1 and 2 and writes the sum to field 3 
 +// The value of field 3 is updated every 500ms (twice per second) 
 + 
 +main() 
 +{ 
 +    SetTickInterval(500);       // Make sure the @Tick function is called twice per second 
 +} 
 + 
 +@Tick(uptime) 
 +{ 
 +    new f1, f2;             // declare local variables 
 +     
 +    f1 = GetField(1);       // set f1 to the value of field 1 
 +    f2 = GetField(2);       // set f2 to the value of field 2 
 +     
 +    SetField(3, f1+f2);     // set the value of field 3 with the sum of f1 and f2 
 +} 
 +</code> 
 + 
 +The example below illustrates the use of a global variable, the use of the main() function to initialize the values, and the @Tick(uptime) call. The program will use field number 1, and count from 100 down to 50, and then starting over. 
 + 
 +<code javascript> 
 +// A simple demo program, counting down from 100 to 50, and then starts over 
 + 
 +new myCounter;                  // Declare a 'global' variable 
 + 
 +main()                          // The main() function will run on startup, once 
 +{ 
 +    SetTickInterval(1000);      // Make sure the @Tick function is called once every 1000ms (1s) 
 +    myCounter = 100;            // Initialize the counter with value 100 
 +} 
 + 
 +@Tick(uptime)                   // The @Tick function will be called once per second 
 +{ 
 +    myCounter = myCounter - 1;  // Count down the counter with 1 
 +     
 +    if(myCounter <= 50) {       // If we reached 50 (or lower) 
 +        myCounter = 100         // ..then set it back to 100 
 +    } 
 +         
 +    SetField(1, myCounter);     // Update field 1 with the counter value 
 +} 
 +</code> 
 + 
 +The example below will run a 3-speed fan based on the input from a temperature sensor on field 1. 
 +Output 1 is used for low speed, output 2 is medium speed, and output 3 is high speed. 
 +The speed is selected based on how much the temperature exceeds a given setpoint (here set to 20.5 degrees C) 
 + 
 +<code javascript> 
 +main() 
 +{ 
 +    SetTickInterval(5000);  // Update every 5s (5000ms) 
 +} 
 + 
 +@Tick(uptime) 
 +{ 
 +    new Float:temp, Float:diff; // Declare "float" variables to handle fractions 
 +     
 +    temp = GetFieldFloat(1);    // Fetch the current temperature from Field 1 
 +    diff = temp - 20.5;         // 20.5 is our setpoint. diff is the differece 
 +     
 +    if(diff > 0.0)              // Over setpoint? 
 +        SetOutput(1, 100);      // ..yes, so enable low speed 
 +    else 
 +        SetOutput(1, 0);        // ..no, so shut off 
 +         
 +    if(diff > 2.0)              // 2 degrees or more over setpoint? 
 +        SetOutput(2, 100);      //..yes, so enable mid-speed 
 +    else 
 +        SetOutput(2, 0); 
 + 
 +    if(diff > 6.0)              // 6 degrees or more over setpoint? 
 +        SetOutput(3, 100);      //..yes, so run full speed 
 +    else 
 +        SetOutput(3, 0); 
 +} 
 +</code>
  
 === State machines === === 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:+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> <code javascript>
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  • Last modified: 2019-09-02 21:29
  • by andreh