ModbusMaster, modbus master

• Questo topic tratta l’utilizzo dell’utilty Modbus Master del programma Toolly per testare la connessione Modbus su di un dispositivo.
• In questo topic viene illustato come utilizzare più FB ModBusMaster in cascata per comunicare con più dispositivi.
• In questo topic un semplice programma di comunicazione Modbus.
• In questo topic suggerimenti su comunicazione con più dispositivi Modbus TCP.

• Se l’oggetto aggiornato non è nell’ultima versione del package, vedi capitolo “Aggiornamento librerie” in questo articolo.
• Gli oggetti obsoleti sono inseriti nella libreria eLLabObsoleteLib fare riferimento al relativo manuale ed al manuale programmazione in formato pdf.

ModbusMaster_v1

Implementa una gestione ottimizzata della acquisizione dei frames modbus di risposta evitando la dichiarazione del parametro IFTime. Tutti gli altri parametri in ingresso rimangono invariati, i parametri Timeout e Delay ora sono definiti di tipo REAL ed occorre impostarne il valore in secondi.

ModbusMaster_v2

Aggiunta gestione ingresso Absolute, se attivo considera indirizzamento assoluto e non viene sottratto 1 all’indirizzo Modbus inviato nel frame di richiesta. Visto che è stato aggiunto il solo parametro di ingresso Absolute mantenendo identico il funzionamento può sostituire la ModbusMaster_v1 nei progetti esistenti.

ModbusMaster_v3

Ingresso Type di definizione tipo di protocollo ora è di tipo MODBUS_PROTOCOL. I parametri in I/O Timeout, Delay e CTime ora sono di tipo TIME.

16#01 Read coil status (Massimo 250 coils)
16#02 Read input status (Massimo 125 inputs)
16#03 Read holding registers (Massimo 125 registri)
16#04 Read input registers (Massimo 125 registri)

      +----+-----------+---+---+---+---+           +----+-----------+-----+--...--+
Query |Node|01/02/03/04|Address|Points |  Response |Node|01/02/03/04|Bytes| Data  |
      +----+-----------+---+---+---+---+           +----+-----------+-----+--...--+

16#05 Force single coil
16#06 Preset single register

      +----+-----+---+---+--+--+           +----+-----+---+---+--+--+
Query |Node|05/06|Address|Data |  Response |Node|05/06|Address|Data |
      +----+-----+---+---+--+--+           +----+-----+---+---+--+--+

16#0F Force Multiple Coils (Massimo 250 coils)
16#10 Preset multiple registers (Massimo 125 registri)

      +----+-----+---+---+---+---+-----+--...--+           +----+-----+---+---+---+---+
Query |Node|0F/10|Address|Points |Bytes| Data  |  Response |Node|0F/10|Address|Points |
      +----+-----+---+---+---+---+-----+--...--+           +----+-----+---+---+---+---+

16#41 Read memory bytes (Funzione custom, massimo 250 bytes)

      +----+--+---+---+---+---+           +----+--+-------+--...--+
Query |Node|41|Address|Points |  Response |Node|41|Points | Data  |
      +----+--+---+---+---+---+           +----+--+-------+--...--+

16#42 Write memory bytes (Funzione custom, massimo 250 bytes)

      +----+--+---+---+---+---+--...--+           +----+--+-------+
Query |Node|42|Address|Points | Data  |  Response |Node|42|Points |
      +----+--+---+---+---+---+--...--+           +----+--+-------+

I codici 16#41 e 16#42 sono stati implementati per compatibilità con i vecchi sistemi programmabili con Remoter.

PROGRAM ST_ModbusMaster
VAR
    i : UDINT; (* Aux counter *)
    SerialOrTCP : BOOL := FALSE; (* FALSE:Serial, TRUE:TCP communication *)
    CaseNr : USINT; (* Program case *)
    Sp : SysSerialPort; (* Serial port *)
    TCPClient : SysTCPClient; (* TCP client management *)
    MMdb : ModbusMaster_v3; (* Modbus master FB *)
    RCoils : ARRAY[0..15] OF BOOL; (* Coil status (Read) *)
    RHRegs : ARRAY[0..15] OF WORD; (* Holding registers (Read) *)
    WCoils : ARRAY[0..15] OF BOOL; (* Coil status (Write) *)
    WHRegs : ARRAY[0..15] OF WORD; (* Holding registers (Write) *)
END_VAR

// *****************************************************************************
// PROGRAM "ST_ModbusMaster"
// *****************************************************************************
// Are executed all possible Modbus commands with a connection over another
// SlimLine. It's possible to test all the three possible Modbus types (Serial
// RTU, serial ascii, TCP).
// -----------------------------------------------------------------------------

    // -------------------------------------------------------------------------
    // INITIALIZATION
    // -------------------------------------------------------------------------
    // Program initializations.

    IF (SysFirstLoop) THEN

        // Serial port settings.

        Sp.COM:=ADR('COM0'); //COM port definition
        Sp.Baudrate:=115200; //Baudrate
        Sp.Parity:='E'; //Parity
        Sp.DataBits:=8; //Data bits
        Sp.StopBits:=1; //Stop bits
        Sp.DTRManagement:=DTR_AUTO_WO_TIMES; //DTR management
        Sp.DTRComplement:=FALSE; //DTR complement
        Sp.EchoFlush:=FALSE; //Received echo flush
        Sp.DTROnTime:=0; //DTR On time delay (mS)
        Sp.DTROffTime:=0; //DTR Off time delay (mS)
        Sp.FlushTm:=0; //Flush time (mS)
        Sp.RxSize:=0; //Rx buffer size
        Sp.TxSize:=0; //Tx buffer size

        // TCP client settings.
        // Port 502 to connect to embed Modbus slave.
        // Port 3000 to connect to ModbusSlave FB example.

        TCPClient.PeerAdd:=ADR('127.0.0.1'); //Peer address
        TCPClient.PeerPort:=3000; //Peer port
        TCPClient.LocalAdd:=ADR('0.0.0.0'); //Local address
        TCPClient.LocalPort:=0; //Local port
        TCPClient.FlushTm:=50; //Flush time (mS)
        TCPClient.LifeTm:=20; //Life time (S)
        TCPClient.RxSize:=128; //Rx buffer size
        TCPClient.TxSize:=128; //Tx buffer size

        // Modbus master settings.

        MMdb.Absolute:=FALSE; //Absolute addressing
        MMdb.Node:=1; //Node number
        MMdb.Timeout:=T#1s; //Timeout time
        MMdb.Delay:=T#100ms; //Delay time
    END_IF;

    // -------------------------------------------------------------------------
    // MODBUS MANAGEMENT
    // -------------------------------------------------------------------------
    // Eseguo selezione canale comunicazione.

    IF NOT(SerialOrTCP) THEN

        // Serial port management.

        Sp(Open:=TRUE); //Serial port management
        MMdb.File:=Sp.File; //File pointer
        MMdb.Type:=MODBUS_PROTOCOL#MDB_RTU; //Modbus protocol type
      //  MMdb.Type:=MODBUS_PROTOCOL#MDB_ASCII; //Modbus protocol type
    ELSE

        // TCP client management.

        TCPClient(Connect:=TRUE); //TCPClient management
        MMdb.File:=TCPClient.File; //File pointer
        MMdb.Type:=MODBUS_PROTOCOL#MDB_TCP; //Modbus protocol type
    END_IF;

    // Manage the modbus master communication.

    MMdb(); //Modbus master
    IF NOT(SysFIsOpen(MMdb.File)) THEN MMdb.Enable:=FALSE; CaseNr:=0; RETURN; END_IF;

    // -------------------------------------------------------------------------
    // PROGRAM CASES
    // -------------------------------------------------------------------------
    // Manage the program cases.

    CASE (CaseNr) OF    

        // ---------------------------------------------------------------------
        // Execute a Force multiple coils.

        0:
        MMdb.Enable:=TRUE; //Modbus enable
        MMdb.FCode:=16#0F; //Modbus function code
        MMdb.Address:=40000; //Modbus register address
        MMdb.Points:=SIZEOF(WCoils); //Modbus register points
        MMdb.Buffer:=ADR(WCoils); //Memory buffer address
        IF NOT(MMdb.Done) THEN RETURN; END_IF;
        MMdb.Enable:=FALSE; //Modbus enable
        CaseNr:=CaseNr+1; //Program case

        // ---------------------------------------------------------------------
        // Execute a Force single coil.

        1:
        MMdb.Enable:=TRUE; //Modbus enable
        MMdb.FCode:=16#05; //Modbus function code
        MMdb.Address:=40000+0; //Modbus register address
        MMdb.Points:=0; //Modbus register points
        MMdb.Buffer:=ADR(WCoils); //Memory buffer address
        IF NOT(MMdb.Done) THEN RETURN; END_IF;
        MMdb.Enable:=FALSE; //Modbus enable
        CaseNr:=CaseNr+1; //Program case

        // ---------------------------------------------------------------------
        // Execute a Read coil status.

        2:
        MMdb.Enable:=TRUE; //Modbus enable
        MMdb.FCode:=16#01; //Modbus function code
        MMdb.Address:=40000+0; //Modbus register address
        MMdb.Points:=SIZEOF(RCoils); //Modbus register points
        MMdb.Buffer:=ADR(RCoils); //Memory buffer address
        IF NOT(MMdb.Done) THEN RETURN; END_IF;
        MMdb.Enable:=FALSE; //Modbus enable
        CaseNr:=CaseNr+1; //Program case

        // ---------------------------------------------------------------------
        // Execute a Preset multiple registers.

        3:
        MMdb.Enable:=TRUE; //Modbus enable
        MMdb.FCode:=16#10; //Modbus function code
        MMdb.Address:=40000+(16/2); //Modbus register address
        MMdb.Points:=SIZEOF(WHRegs)/2; //Modbus register points
        MMdb.Buffer:=ADR(WHRegs); //Memory buffer address
        IF NOT(MMdb.Done) THEN RETURN; END_IF;
        MMdb.Enable:=FALSE; //Modbus enable
        CaseNr:=CaseNr+1; //Program case

        // ---------------------------------------------------------------------
        // Execute a Preset single register.

        4:
        MMdb.Enable:=TRUE; //Modbus enable
        MMdb.FCode:=16#06; //Modbus function code
        MMdb.Address:=40000+(16/2); //Modbus register address
        MMdb.Points:=0; //Modbus register points
        MMdb.Buffer:=ADR(WHRegs[0]); //Memory buffer address    
        IF NOT(MMdb.Done) THEN RETURN; END_IF;
        MMdb.Enable:=FALSE; //Modbus enable
        CaseNr:=CaseNr+1; //Program case

        // ---------------------------------------------------------------------
        // Execute a Read holding registers.

        5:
        MMdb.Enable:=TRUE; //Modbus enable
        MMdb.FCode:=16#03; //Modbus function code
        MMdb.Address:=40000+(16/2); //Modbus register address
        MMdb.Points:=SIZEOF(RHRegs)/2; //Modbus register points
        MMdb.Buffer:=ADR(RHRegs); //Memory buffer address
        IF NOT(MMdb.Done) THEN RETURN; END_IF;
        MMdb.Enable:=FALSE; //Modbus enable
        CaseNr:=0; //Program case
    END_CASE;

// [End of file]