packet length more bytes than expected error

[ranjithphptech]

root@ubuntu:/home/rkphptech# php /var/www/html/modbus-tcp-client-master/examples/write_usb_serial.php
RTU Binary to sent (in hex):   0106000d0001d9c9
2023-01-25 10:12:55.876190: [debug] msg: "Connected"
2023-01-25 10:12:55.880604: [debug] msg: "Data sent", data: array (
  1 => '0106000d0001d9c9',
)
2023-01-25 10:12:55.917155: [debug] msg: "Polling data"
2023-01-25 10:12:55.917287: [debug] msg: "Stream 37 @ index: 0 received data: ", data: array (
  1 => '0106000d0001d9c9',
)
An exception occurred
packet length more bytes than expected
#0 /var/www/html/modbus-tcp-client-master/examples/write_usb_serial.php(16): ModbusTcpClient\Utils\Packet::isCompleteLengthRTU()
#1 /var/www/html/modbus-tcp-client-master/src/Network/StreamHandler.php(78): {closure}()
#2 /var/www/html/modbus-tcp-client-master/src/Network/BinaryStreamConnection.php(60): ModbusTcpClient\Network\BinaryStreamConnection->receiveFrom()
#3 /var/www/html/modbus-tcp-client-master/src/Network/BinaryStreamConnection.php(83): ModbusTcpClient\Network\BinaryStreamConnection->receive()
#4 /var/www/html/modbus-tcp-client-master/examples/write_usb_serial.php(32): ModbusTcpClient\Network\BinaryStreamConnection->sendAndReceive()
#5 {main}

my code
use ModbusTcpClient\Network\BinaryStreamConnection;
use ModbusTcpClient\Packet\ModbusFunction\WriteSingleRegisterRequest;
use ModbusTcpClient\Packet\ModbusFunction\WriteSingleRegisterResponse;
use ModbusTcpClient\Packet\RtuConverter;
use ModbusTcpClient\Utils\Packet;

require DIR . '/../vendor/autoload.php';
require DIR . '/logger.php';

$connection = BinaryStreamConnection::getBuilder()
->setUri('/dev/ttyUSB0')
->setProtocol('serial')
->setIsCompleteCallback(static function ($binaryData, $streamIndex): bool {
return Packet::isCompleteLengthRTU($binaryData);
})
->setLogger(new EchoLogger())
->build();

[aldas]

Seems that Packet::isCompleteLengthRTU is little buggy with for write* responses.

This should work for FC6 response:

->setIsCompleteCallback(static function ($binaryData, $streamIndex): bool {
return strlen($binaryData) == 8;
})

FC6 RTU response has 6 bytes of data + 2 bytes for CRC

modbus-tcp-client/src/Packet/ModbusFunction/WriteSingleRegisterResponse.php

Lines 17 to 20 in 48c46a8

	* \x03 - unit id
	* \x06 - function code
	* \x00\x02 - start address
	* \xFF\x00 - register data

[aldas]

Hey, I have released new version 3.1.1 that fixes Packet::isCompleteLengthRTU to understand write response length correctly

[aldas]

@ranjithphptech could you recheck with latest version?