setHost($config['host'])->setLog( function ($log){ echo(''.$log."
\n");} )->open();
/**
* Reading a value from the device.
*
* @param $client ModbusTcpClient
* @param $variable
* @param $valueLength
* @return void
*/
function readEasyControlsVariable($client, $variable, $valueLength )
{
// THIS IS A RELLY BAD BAD DESIGN BY HELIOS:
// You have to write the variable name into the same adress for all requests.
// And than you have to read the value from the same adress.
// This has nothing to do which the modbus tcp spec!
// BE CAREFUL OF RACE CONDITIONS:
// If another client is writing the variable name into the register at the same time, then you maybe getting a response for another variable in the 2nd request (head->table).
// It is better to shut down your smarthome if it is requesting values via modbus tcp the same time.
// I'll repeat: This is a VERY POOR AND BAD DESIGN BY HELIOS!
// And that has nothing to do with modbus tcp, which is itself a robust mechanism.
// Cite from the documentation:
//
// Das Lesen von Variablen erfordert ein zweistufiges Vorgehen:
// 1. Zuerst muss die Bezeichnung der zu lesenden Variable im Format „vXXXXX\0“ als HEX-Zeichen codiert in die
// Modbus-Register ab Registeradresse 1 geschrieben werden.
// 2. Mit der anschließenden Abfrage kann die angeforderte Variable ab der Registeradresse 1 gelesen werden. Die an-
// geforderte Variable wird dann im Format „vXXXXX=YYYYY...\0“ (als HEX-Zeichen codiert) zurückgegeben.
$var = $variable."\x00\x00"; // Variable name + NUL
$startReference = 1; // Immer Startadresse 1.
echo "result ready\n";
$client->writeMultipleHoldingRegisters()->setUnit(180)->write($startReference,$var);
echo "\n";
// 8 bytes from startadress 1
$result = $client->readMultipleHoldingRegisters()->setUnit(180)->readFrom($startReference,$valueLength);
$length = unpack("C",substr($result,0,1))[1];
echo "Laenge: $length\n";
$value = substr(rtrim($result,"\x00"),1);
echo "Value of '$variable': $value\n";
}
// get outdoor temperature from helios kwl modbus tcp
readEasyControlsVariable( $client,"v00104",7);
// get system date from helios kwl modbus tcp
readEasyControlsVariable($client,"v00004",9);
$client->close();
?>