Not Reading the Input Registers

[V3NK47]

This is the code I'm trying to retrieve data from the register.

require 'PhpSerialModbus.php';

$modbus = new PhpSerialModbus;

$modbus->deviceInit('COM3',19200,'none',8,1,'none');

$modbus->deviceOpen();

$startaddress = 3371;

while($startaddress!=3380)
{
$modbus->debug = true;
echo $hex_addr = strval(dechex($startaddress));
echo "
";
echo $startaddress;
echo "
";
$result=$modbus->sendQuery(11,3,$hex_addr,2);
if(print_r($result)){
echo "
";
$startaddress++;
}

}

Output : I receive null output.

The datasheet of the device I'm trying to connect.

I'm not sure what I'm missing. There are not a lot of community on internet to research about.

Kindly help me through. Thanks in advance.

[menardany]

$hex_addr = "D2B"
The way sendQuery() parses the data, it sends "D20B" (53771)

will need to add str_pad($hex_addr,4,"0",STR_PAD_LEFT); in your code to make it a 4 character string

or add $registerAddress = str_pad($registerAddress,4,"0",STR_PAD_LEFT); at line 111 of PhpSerialModbus.php