实例介绍
【实例简介】
【实例截图】
【实例截图】
【核心代码】
<?php
define('READ_HOLDING_REGISTERS', 0x03);
define('READ_INPUT_REGISTERS', 0x04);
define('MBAP_HEADER_SIZE', 7); //7bytes
define('MODBUS_TCP_MAX_ADU_SIZE', 260); //260bytes
define('MODBUS_TCP_MIN_RESPONSE_DATA_SIZE', 2); //2bytes
define('MODBUS_TCP_UNPACK_FUNC_BYTECOUNT', 'Cfunc/Cbyte_count');
//check MODBUS TCP MBAP header
function check_mbap_header(&$header)
{
assert(is_array($header));
if($header['pid'] !== 0)
{
return false;
}
if($header['len'] < MODBUS_TCP_MIN_RESPONSE_DATA_SIZE || $header['len'] > (MODBUS_TCP_MAX_ADU_SIZE - MBAP_HEADER_SIZE 1))
{
return false;
}
return true;
}
//check response from
function modbus_tcp_check_read_reg_response_pdu(&$pdu, $func, &$exception, $byte_count)
{
assert(is_string($pdu));
assert(is_int($func));
assert(isset($exception));
assert(is_int($byte_count));
//check function code and byte count
if( ord($pdu{0}) == $func and $byte_count == ord($pdu{1}))
{
return true;
}
$exception = 0;
if(ord($pdu{0}) === ($func | 0x80))
{
$exception = ord($pdu{1});
}
return false;
}
//generate MODBUS TCP read holding register(s) or input register(s) command
function modbus_tcp_build_read_reg_cmd(&$tid, $uid, $func, $address, $quantity)
{
assert(is_int($tid));
assert(is_int($uid));
assert($func === READ_HOLDING_REGISTERS || $func === READ_INPUT_REGISTERS);
assert(is_int($func));
assert(is_int($quantity));
$pdu = pack('Cnn', $func, $address, $quantity);
$header = pack('nxxnC', $tid, strlen($pdu) 1, $uid);
return ($header . $pdu);
}
//receive TCP packet until done it
function tcp_recv_until_done($fp, &$buffer, $length)
{
assert(is_resource($fp));
assert(is_int($length));
$count = 0;
while($length > $count)
{
$tmp = fread($fp, $length - $count);
if(!$tmp)
{
return false;
}
$count = strlen($tmp);
$buffer .= $tmp;
}
return true;
}
//convert MBAP header to array
function unpack_mbap_header(&$buffer)
{
assert(is_string($buffer));
//tid,pid,len
$tmp = unpack('ntid/npid/nlen', $buffer);
$tmp['len'] -= 1; // remove uid size
return $tmp;
}
// receive MODBUS TCP ADU and then callback response handler
function modbus_tcp_recv_adu($fp, &$response_handlers, &$error_msg)
{
assert(is_resource($fp));
assert(is_array($response_handlers));
//read packet header
$packed_header = '';
if(!tcp_recv_until_done($fp, $packed_header, MBAP_HEADER_SIZE))
{
return false;
}
//check packet header
$unpacked_header = unpack_mbap_header($packed_header);
if(!check_mbap_header($unpacked_header))
{
return false;
}
//read PDU
$packed_pdu = '';
if(!tcp_recv_until_done($fp, $packed_pdu, $unpacked_header['len']))
{
return false;
}
//validate TID
if(!isset($response_handlers[$unpacked_header['tid']]))
{
return false;
}
//callback response handler
assert(isset($response_handlers[$unpacked_header['tid']]['handler']));
assert(isset($response_handlers[$unpacked_header['tid']]['address']));
assert(isset($response_handlers[$unpacked_header['tid']]['data']));
return $response_handlers[$unpacked_header['tid']]['handler']($response_handlers[$unpacked_header['tid']]['address'], $packed_pdu, $error_msg, $response_handlers[$unpacked_header['tid']]['data']);
}
//send tcp packet until done it
function tcp_send_until_done($fp, &$buffer)
{
assert(is_resource($fp) and is_string($buffer));
$length = strlen($buffer);
if($length == 0)
return false;
$count = 0;
while($length > $count)
{
$tmp = fwrite($fp, substr($buffer, $count, $length - $count));
if(!$tmp)
return false;
$count = $tmp;
}
return true;
}
//make MODBUS TCP Transaction
function modbus_tcp_transact($fp, &$commands, &$response_handlers, &$error_msg)
{
assert(is_array($commands));
//send modbus tcp request(s)
for($i = 0; $i < count($commands); $i)
{
if(!tcp_send_until_done($fp, $commands[$i]))
{
return false;
}
}
//receive modbus tcp response(s)
for($i = 0; $i < count($commands); $i)
{
if(!modbus_tcp_recv_adu($fp, $response_handlers, $error_msg))
{
return false;
}
}
return true;
}
function read_holding_registers_0_handler($address, &$pdu, &$error_msg, &$data)
{
assert(is_int($address));
assert(is_string($pdu));
assert(is_string($error_msg));
$exception = 0;
if(!modbus_tcp_check_read_reg_response_pdu($pdu, READ_HOLDING_REGISTERS, $exception, 4))
{
if($exception == 0)
{
//invalid protocol
return false;
}
//send back exception code
return true;
}
$unpacked_pdu = unpack(MODBUS_TCP_UNPACK_FUNC_BYTECOUNT . '/ndata1low/ndata1high', $pdu);
printf("holding register address %d-%d: %d\n", $address, $address 1, ($unpacked_pdu['data1high']<<16) | $unpacked_pdu['data1low']);
return true;
}
function read_holding_registers_300_handler($address, &$pdu, &$error_msg, &$data)
{
assert(is_int($address));
assert(is_string($pdu));
assert(is_string($error_msg));
$exception = 0;
if(!modbus_tcp_check_read_reg_response_pdu($pdu, READ_HOLDING_REGISTERS, $exception, 4))
{
if($exception == 0)
{
//invalid protocol
return false;
}
//send back exception code
return true;
}
$unpacked_pdu = unpack(MODBUS_TCP_UNPACK_FUNC_BYTECOUNT . '/Ndata2', $pdu);
printf("holding register address %d-%d: %d\n", $address, $address 1, $unpacked_pdu['data2']);
return true;
}
function read_inpu_registers_0_handler($address, &$pdu, &$error_msg, &$data)
{
assert(is_int($address));
assert(is_string($pdu));
assert(is_string($error_msg));
$exception = 0;
if(!modbus_tcp_check_read_reg_response_pdu($pdu, READ_INPUT_REGISTERS, $exception, 4))
{
if($exception == 0)
{
//invalid protocol
return false;
}
//send back exception code
return true;
}
$unpacked_pdu = unpack(MODBUS_TCP_UNPACK_FUNC_BYTECOUNT . '/ndata3high/ndata3low', $pdu);
$data3 = unpack('f', pack('SS', $unpacked_pdu['data3high'], $unpacked_pdu['data3low']));
printf("input register address %d-%d: %f\n", $address, $address 1, $data3[1]);
return true;
}
function read_inpu_registers_200_handler($address, &$pdu, &$error_msg, &$data)
{
assert(is_int($address));
assert(is_string($pdu));
assert(is_string($error_msg));
$exception = 0;
if(!modbus_tcp_check_read_reg_response_pdu($pdu, READ_INPUT_REGISTERS, $exception, 8))
{
if($exception == 0)
{
//invalid protocol
return false;
}
//send back exception code
return true;
}
$unpacked_pdu = unpack(MODBUS_TCP_UNPACK_FUNC_BYTECOUNT . '/nd3/nd2/nd1/nd0', $pdu);
$data4 = unpack('d', pack('SSSS', $unpacked_pdu['d3'], $unpacked_pdu['d2'], $unpacked_pdu['d1'], $unpacked_pdu['d0']));
printf("input register address %d-%d: %f\n", $address, $address 3, $data4[1]);
return true;
}
//connect 127.0.0.1, port:502, timeout:3sec
$fp = @fsockopen('tcp://127.0.0.1', 502, $errno, $errstr, 3);
if(!$fp)
{
printf("can\'t connect modbus tcp device\n");
die();
}
//set send/receive timeout = 3sec
if(!stream_set_timeout($fp, 3))
{
fclose($fp);
printf("failed to change communication timeout\n");
die();
}
$tid = 0; //initialize TID
$test_commands = array();
$test_response_handlers = array();
//read holding register address:0 quantity:2 type: long
$test_commands[] = modbus_tcp_build_read_reg_cmd($tid, 1, READ_HOLDING_REGISTERS, 0, 2);
$response_handlers[$tid] = array();
$response_handlers[$tid]['address'] = 0;
$response_handlers[$tid]['handler'] = 'read_holding_registers_0_handler';
//read holding register address:300 quantity:2 type: long inverse
$test_commands[] = modbus_tcp_build_read_reg_cmd($tid, 1, READ_HOLDING_REGISTERS, 300, 2);
$response_handlers[$tid] = array();
$response_handlers[$tid]['address'] = 300;
$response_handlers[$tid]['handler'] = 'read_holding_registers_300_handler';
//read input register address:0 quantity:2 type: float
$test_commands[] = modbus_tcp_build_read_reg_cmd($tid, 1, READ_INPUT_REGISTERS, 0, 2);
$response_handlers[$tid] = array();
$response_handlers[$tid]['address'] = 0;
$response_handlers[$tid]['handler'] = 'read_inpu_registers_0_handler';
//read input register address:0 quantity:4 type: double
$test_commands[] = modbus_tcp_build_read_reg_cmd($tid, 1, READ_INPUT_REGISTERS, 200, 4);
$response_handlers[$tid] = array();
$response_handlers[$tid]['address'] = 200;
$response_handlers[$tid]['handler'] = 'read_inpu_registers_200_handler';
if(!modbus_tcp_transact($fp, $test_commands, $response_handlers))
{
fclose($fp);
printf("shit happen!\n");
die();
}
fclose($fp);
?>
标签： 代码
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