File modules/modbusy/request/MultibyteRequest.class.php

Last commit: Thu Dec 26 19:50:18 2024 +0100	Jan Dankert	New: ModbusTCP for later use in the scriptbox.


     1 <?php
     2 namespace modbusy\request;
     3 
     4 
     5 abstract class MultibyteRequest extends  Request
     6 {
     7     const ERRORS = [
     8 1 =>	'Illegal Function 	Function code received in the query is not recognized or allowed by server',
     9 2 =>	'Illegal Data Address 	Data address of some or all the required entities are not allowed or do not exist in server',
    10 3 =>	'Illegal Data Value 	Value is not accepted by server',
    11 4 =>	'Server Device Failure 	Unrecoverable error occurred while server was attempting to perform requested action',
    12 5 =>	'Acknowledge 	Server has accepted request and is processing it, but a long duration of time is required. This response is returned to prevent a timeout error from occurring in the client. client can next issue a Poll Program Complete message to determine whether processing is completed',
    13 6 =>	'Server Device Busy 	Server is engaged in processing a long-duration command; client should retry later',
    14 7 =>	'Negative Acknowledge 	Server cannot perform the programming functions; client should request diagnostic or error information from server',
    15 8 =>	'Memory Parity Error 	Server detected a parity error in memory; client can retry the request',
    16 10=> 	'Gateway Path Unavailable 	Specialized for Modbus gateways: indicates a misconfigured gateway',
    17 11=> 	'Gateway Target Device Failed to Respond',
    18     ];
    19 
    20     protected function request($command )
    21     {
    22         $this->log("Sending");
    23         $this->transactionId = rand(0,65535);
    24         $transaction = pack("n",$this->transactionId);
    25 
    26         $this->logHex("Sending transaction",$transaction);
    27         //  When sending a Modbus TCP frame, the frame is split into 6 different sections:
    28         //1)      Transaction Identifier ( 2 bytes )
    29         //2)      Protocol Identifier (2 bytes)
    30         //3)      Length Field (2 bytes)
    31         //4)      Unit Identifier (1 byte)
    32         //5)      Function Code (1 byte)
    33         //6)      Data bytes (n bytes)
    34         $bytes = fwrite($this->socket,$transaction);
    35         if   ( $bytes !== 2 )
    36             throw new \InvalidArgumentException("could not write transaction id to socket");
    37 
    38         $bytes = fwrite($this->socket,self::PROTOCOL_IDENTIFIER);
    39         $this->logHex("Sending protocol",self::PROTOCOL_IDENTIFIER);
    40         if   ( $bytes !== 2 )
    41             throw new \InvalidArgumentException("could not write 00 to socket");
    42 
    43         // length
    44         $length = strlen($command)+2;
    45         $this->logHex("sending length",pack("n",$length));
    46         fwrite($this->socket,pack("n",$length) ); // 2 bytes
    47 
    48         $this->logHex("sending unit",pack("C",$this->unitId));
    49         fwrite($this->socket,pack("C",$this->unitId) ); // unit identifier 1 byte
    50 
    51         $this->logHex("sending function code",pack("C",$this->functionCode));
    52         fwrite($this->socket,pack("C",$this->functionCode) );
    53 
    54         $this->logHexDump( "sending command",$command);
    55         fwrite($this->socket,$command );
    56 
    57         $this->log("now getting data...");
    58         $transactionResponse = fgets($this->socket,2+1);
    59         $this->logHex("Transaction",$transactionResponse);
    60         if   ( $transaction != $transactionResponse )
    61             throw new \InvalidArgumentException("transaction from modbus slave '".bin2hex($transactionResponse)."' does not match ours '".bin2hex($transaction)."'");
    62         $protocol = fgets($this->socket,2+1);
    63         if   ( $protocol != self::PROTOCOL_IDENTIFIER )
    64             throw new \InvalidArgumentException("protocol does not match");
    65         $this->logHex("Protocol",$protocol);
    66         $length = unpack("n",fgets($this->socket,2+1))[1];
    67         $this->log("Response-Length ".$length.' bytes');
    68         $response = fgets($this->socket,$length+1);
    69 
    70         $unitResponse = unpack("C",substr($response,0,1))[1];
    71         $this->log("Unit ".$unitResponse);
    72 
    73         $functionResponse = unpack("C",substr($response,1,1))[1];
    74         $this->log("Function code ".$functionResponse);
    75 
    76         $data = substr($response,2); // truncate unitId and functionCode (1+1=2 bytes)
    77         $this->logHexDump("Result",$data);
    78 
    79         if   ( $functionResponse == $this->functionCode ) {
    80             // success
    81 
    82             return $data;
    83         }
    84         elseif   ( $functionResponse == $this->functionCode + 128 ) {
    85 
    86             if   ( strlen($data) == 1 ) {
    87                 $errorCode = unpack("C",$data)[1];
    88                 if   ( isset(self::ERRORS[$errorCode]) )
    89                     throw new \InvalidArgumentException("server error: ".self::ERRORS[$errorCode]);
    90 
    91                 else
    92                     throw new \InvalidArgumentException("server error with unknown error code ".$errorCode);
    93             }
    94             else
    95                 throw new \InvalidArgumentException("server error with unknown error data: '".bin2hex($data));
    96         }
    97         else {
    98             throw new \InvalidArgumentException("server error: function in response is ".$functionResponse." and not the called function ".$function.". Data is '".bin2hex($data)."'");
    99         }
   100     }
   101 }



Download modules/modbusy/request/MultibyteRequest.class.php


History
Thu, 26 Dec 2024 19:50:18 +0100	Jan Dankert	New: ModbusTCP for later use in the scriptbox.