757 lines
27 KiB
C++
757 lines
27 KiB
C++
#include "modbus_tcp_client.h"
|
|
#include <sys/select.h> // For select() timeout
|
|
|
|
ModbusTCPClient::ModbusTCPClient(const char* ip, int port, int numCoils, int numDI, int numIR, int numHR,
|
|
int startCoils, int startDI, int startIR, int startHR)
|
|
: serverIP(ip), serverPort(port), socketFD(-1), transactionID(1),
|
|
numCoils(numCoils), numDiscreteInputs(numDI), numInputRegisters(numIR), numHoldingRegisters(numHR),
|
|
startCoils(startCoils), startDiscreteInputs(startDI), startInputRegisters(startIR), startHoldingRegisters(startHR) {
|
|
|
|
// Allocate memory dynamically based on provided sizes
|
|
coilsRead = new bool[numCoils]();
|
|
coilsWrite = new bool[numCoils]();
|
|
discreteInputs = new bool[numDiscreteInputs]();
|
|
|
|
inputRegisters = new uint16_t[numInputRegisters]();
|
|
holdingRegistersRead = new uint16_t[numHoldingRegisters]();
|
|
holdingRegistersWrite = new uint16_t[numHoldingRegisters]();
|
|
}
|
|
|
|
ModbusTCPClient::ModbusTCPClient(const char* ip, int port)
|
|
: serverIP(ip), serverPort(port), socketFD(-1) {
|
|
/*
|
|
This constructor is if the user manually wants to call MODBUS TCP functions and not
|
|
use readAll() and writeAll() and the setters/getters
|
|
*/
|
|
|
|
// Set everything to nullptr so that readAll() and writeAll() won't work
|
|
coilsRead = nullptr;
|
|
coilsWrite = nullptr;
|
|
discreteInputs = nullptr;
|
|
|
|
inputRegisters = nullptr;
|
|
holdingRegistersRead = nullptr;
|
|
holdingRegistersWrite = nullptr;
|
|
}
|
|
|
|
ModbusTCPClient::~ModbusTCPClient() {
|
|
delete[] coilsRead;
|
|
delete[] coilsWrite;
|
|
delete[] discreteInputs;
|
|
|
|
delete[] inputRegisters;
|
|
delete[] holdingRegistersRead;
|
|
delete[] holdingRegistersWrite;
|
|
}
|
|
|
|
void ModbusTCPClient::setStartAddresses(int startCoils, int startDI, int startIR, int startHR) {
|
|
this->startCoils = startCoils;
|
|
this->startDiscreteInputs = startDI;
|
|
this->startInputRegisters = startIR;
|
|
this->startHoldingRegisters = startHR;
|
|
}
|
|
|
|
bool ModbusTCPClient::connectServer() {
|
|
// Step 1: If socket is already open, verify it's still connected
|
|
if (socketFD != -1) {
|
|
struct timeval timeout;
|
|
timeout.tv_sec = 0;
|
|
timeout.tv_usec = 100000; // 100ms timeout for connection check
|
|
|
|
fd_set read_fds;
|
|
FD_ZERO(&read_fds);
|
|
FD_SET(socketFD, &read_fds);
|
|
|
|
int result = select(socketFD + 1, &read_fds, NULL, NULL, &timeout);
|
|
|
|
if (result == 0) {
|
|
// No error in select, socket is still connected
|
|
printf("MODBUS_TCP_CLIENT: Already connected to MODBUS server\n");
|
|
return true;
|
|
} else {
|
|
// Connection is broken, close and reset
|
|
printf("MODBUS_TCP_CLIENT: Warning: Connection lost, reconnecting...\n");
|
|
disconnectServer();
|
|
}
|
|
}
|
|
|
|
// Step 2: Create a new socket
|
|
for (int attempts = 0; attempts < 5; attempts++) { // Retry up to 5 times
|
|
socketFD = socket(AF_INET, SOCK_STREAM, 0);
|
|
if (socketFD < 0) {
|
|
printf("MODBUS_TCP_CLIENT: Could not create socket\n");
|
|
return false;
|
|
}
|
|
|
|
struct sockaddr_in serverAddr;
|
|
serverAddr.sin_family = AF_INET;
|
|
serverAddr.sin_port = htons(serverPort);
|
|
inet_pton(AF_INET, serverIP, &serverAddr.sin_addr);
|
|
|
|
// Step 3: Attempt to connect
|
|
printf("MODBUS_TCP_CLIENT: Attempting to connect to MODBUS server (Try %d)...\n", attempts + 1);
|
|
if (connect(socketFD, (struct sockaddr*)&serverAddr, sizeof(serverAddr)) == 0) {
|
|
printf("MODBUS_TCP_CLIENT: Connected to MODBUS server at %s:%d\n", serverIP, serverPort);
|
|
return true;
|
|
}
|
|
|
|
printf("MODBUS_TCP_CLIENT: Connection failed, retrying...\n");
|
|
disconnectServer(); // Close socket before retrying
|
|
usleep(100000); // Wait 100ms before retrying
|
|
}
|
|
}
|
|
|
|
void ModbusTCPClient::disconnectServer() {
|
|
if (socketFD != -1) {
|
|
close(socketFD);
|
|
socketFD = -1;
|
|
printf("MODBUS_TCP_CLIENT: Disconnected from MODBUS server\n");
|
|
}
|
|
}
|
|
|
|
void ModbusTCPClient::setTimeout(int milliseconds) {
|
|
timeoutMilliseconds = milliseconds;
|
|
printf("MODBUS_TCP_CLIENT: Timeout set to %d ms\n", timeoutMilliseconds);
|
|
}
|
|
|
|
bool ModbusTCPClient::isConnected() const {
|
|
return socketFD != -1;
|
|
}
|
|
|
|
bool ModbusTCPClient::reconnectServer() {
|
|
printf("MODBUS_TCP_CLIENT: Attempting manual reconnection...\n");
|
|
disconnectServer();
|
|
return connectServer();
|
|
}
|
|
|
|
bool ModbusTCPClient::sendRequest(uint8_t* request, int requestSize) {
|
|
// Ensure we're connected before sending
|
|
if (socketFD == -1) {
|
|
printf("MODBUS_TCP_CLIENT: Connection lost. Attempting to reconnect...\n");
|
|
if (!connectServer()) {
|
|
printf("MODBUS_TCP_CLIENT: Reconnection failed. Cannot send request.\n");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
int bytesSent = write(socketFD, request, requestSize);
|
|
if (bytesSent <= 0) { // Detect broken connection during write
|
|
printf("MODBUS_TCP_CLIENT: Write failed, connection lost. Disconnecting...\n");
|
|
disconnectServer();
|
|
return false;
|
|
}
|
|
|
|
return bytesSent == requestSize;
|
|
return bytesSent == requestSize;
|
|
}
|
|
|
|
bool ModbusTCPClient::receiveResponse(uint8_t* response, int expectedSize) {
|
|
int totalBytesReceived = 0;
|
|
|
|
while (totalBytesReceived < expectedSize) {
|
|
struct timeval timeout;
|
|
timeout.tv_sec = timeoutMilliseconds / 1000; // Convert ms to seconds
|
|
timeout.tv_usec = (timeoutMilliseconds % 1000) * 1000; // Convert remaining ms to µs
|
|
|
|
fd_set read_fds;
|
|
FD_ZERO(&read_fds);
|
|
FD_SET(socketFD, &read_fds);
|
|
|
|
// Use select() to wait for data before reading
|
|
int ready = select(socketFD + 1, &read_fds, NULL, NULL, &timeout);
|
|
if (ready == 0) { // Timeout case
|
|
printf("MODBUS_TCP_CLIENT: Timeout waiting for MODBUS response. Disconnecting...\n");
|
|
disconnectServer(); // Close socket and reset socketFD
|
|
return false;
|
|
} else if (ready < 0) { // Select failed
|
|
printf("MODBUS_TCP_CLIENT: Select failed. Disconnecting...\n");
|
|
disconnectServer(); // Close socket and reset socketFD
|
|
return false;
|
|
}
|
|
|
|
// Read available data
|
|
int bytesReceived = read(socketFD, response + totalBytesReceived, expectedSize - totalBytesReceived);
|
|
if (bytesReceived <= 0) { // Connection lost or no data received
|
|
printf("MODBUS_TCP_CLIENT: Connection lost. Disconnecting...\n");
|
|
disconnectServer(); // Close socket and reset socketFD
|
|
return false;
|
|
}
|
|
|
|
totalBytesReceived += bytesReceived;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
void ModbusTCPClient::buildReadRequest(uint8_t* buffer, ModbusFunction functionCode, uint16_t startAddr, uint16_t quantity) {
|
|
transactionID++;
|
|
|
|
// Transaction ID
|
|
buffer[0] = transactionID >> 8;
|
|
buffer[1] = transactionID & 0xFF;
|
|
// Protocol ID, always 00 00
|
|
buffer[2] = 0x00;
|
|
buffer[3] = 0x00;
|
|
// Length (remaining bytes after Unit ID)
|
|
buffer[4] = 0x00;
|
|
buffer[5] = 0x06;
|
|
// Unit ID (Slave Address)
|
|
buffer[6] = 0x01;
|
|
// Function code
|
|
buffer[7] = static_cast<uint8_t>(functionCode);
|
|
// Start Address
|
|
buffer[8] = startAddr >> 8;
|
|
buffer[9] = startAddr & 0xFF;
|
|
// Quantity (How many coils to read)
|
|
buffer[10] = quantity >> 8;
|
|
buffer[11] = quantity & 0xFF;
|
|
}
|
|
|
|
void ModbusTCPClient::buildWriteSingleRequest(uint8_t* buffer, ModbusFunction functionCode, uint16_t address, uint16_t value) {
|
|
transactionID++;
|
|
|
|
buffer[0] = transactionID >> 8;
|
|
buffer[1] = transactionID & 0xFF;
|
|
buffer[2] = 0x00;
|
|
buffer[3] = 0x00;
|
|
buffer[4] = 0x00;
|
|
buffer[5] = 0x06;
|
|
buffer[6] = 0x01;
|
|
buffer[7] = static_cast<uint8_t>(functionCode);
|
|
buffer[8] = address >> 8;
|
|
buffer[9] = address & 0xFF;
|
|
buffer[10] = value >> 8;
|
|
buffer[11] = value & 0xFF;
|
|
}
|
|
|
|
void ModbusTCPClient::buildWriteMultipleRequest(uint8_t* buffer, ModbusFunction functionCode, uint16_t address, uint16_t count, const void* values, uint8_t byteCount) {
|
|
transactionID++;
|
|
|
|
// MODBUS TCP Header
|
|
buffer[0] = transactionID >> 8;
|
|
buffer[1] = transactionID & 0xFF;
|
|
buffer[2] = 0x00; // Protocol ID (always 0x0000)
|
|
buffer[3] = 0x00;
|
|
buffer[4] = 0x00; // Length (remaining bytes after Unit ID)
|
|
buffer[5] = 7 + byteCount;
|
|
buffer[6] = 0x01; // Unit ID
|
|
buffer[7] = static_cast<uint8_t>(functionCode); // Function Code (0x0F for coils, 0x10 for registers)
|
|
buffer[8] = address >> 8; // Start address high byte
|
|
buffer[9] = address & 0xFF; // Start address low byte
|
|
buffer[10] = count >> 8; // Quantity high byte
|
|
buffer[11] = count & 0xFF; // Quantity low byte
|
|
buffer[12] = byteCount; // Byte count
|
|
|
|
// Copy data payload manually (instead of memcpy)
|
|
const uint8_t* data = (const uint8_t*)values;
|
|
for (uint8_t i = 0; i < byteCount; i++) {
|
|
buffer[13 + i] = data[i];
|
|
}
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readCoil(int address, bool &coilState) {
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_COIL, address, 1);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
uint8_t response[10]; // Expecting 10 bytes
|
|
if (!receiveResponse(response, 10)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure function code matches the request (allowing for server behavior)
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_COIL)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_COIL), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Extract coil state (only first bit is used)
|
|
coilState = (response[9] & 0x01) != 0; // Adjusted index based on 10-byte response
|
|
return ModbusError::NONE;
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readMultipleCoils(int address, int count, bool coilStates[]) {
|
|
if (count < 1 || count > 2000) {
|
|
printf("MODBUS_TCP_CLIENT: Invalid coil count (1-2000 allowed)\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_COIL, address, count);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
// Expected response size: Fixed header (9) + variable byte count
|
|
int byteCount = (count + 7) / 8; // 1 byte per 8 coils
|
|
int expectedSize = 9 + byteCount;
|
|
|
|
uint8_t response[256]; // Ensure buffer is large enough
|
|
if (!receiveResponse(response, expectedSize)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure the function code matches
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_COIL)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_COIL), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Read coil values
|
|
for (int i = 0; i < count; i++) {
|
|
int byteIndex = 9 + (i / 8); // Data starts at index 9
|
|
int bitIndex = i % 8;
|
|
coilStates[i] = (response[byteIndex] >> bitIndex) & 0x01;
|
|
}
|
|
|
|
return ModbusError::NONE;
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readDiscreteInput(int address, bool &discreteInput) {
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_DISCRETE_INPUT, address, 1);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
uint8_t response[10]; // Expected response size
|
|
if (!receiveResponse(response, 10)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure function code matches the request
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_DISCRETE_INPUT)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_DISCRETE_INPUT), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Extract single discrete input state
|
|
discreteInput = (response[9] & 0x01) != 0;
|
|
return ModbusError::NONE; // Success
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readMultipleDiscreteInputs(int address, int count, bool discreteInputs[]) {
|
|
if (count < 1 || count > 2000) {
|
|
printf("MODBUS_TCP_CLIENT: Invalid discrete input count (1-2000 allowed)\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_DISCRETE_INPUT, address, count);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
// Expected response size: Fixed header (9) + variable byte count
|
|
int byteCount = (count + 7) / 8; // 1 byte per 8 inputs
|
|
int expectedSize = 9 + byteCount;
|
|
|
|
uint8_t response[256]; // Ensure buffer is large enough
|
|
if (!receiveResponse(response, expectedSize)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure the function code matches
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_DISCRETE_INPUT)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_DISCRETE_INPUT), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Read discrete input values
|
|
for (int i = 0; i < count; i++) {
|
|
int byteIndex = 9 + (i / 8); // Data starts at index 9
|
|
int bitIndex = i % 8;
|
|
discreteInputs[i] = (response[byteIndex] >> bitIndex) & 0x01;
|
|
}
|
|
|
|
return ModbusError::NONE;
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readHoldingRegister(int address, uint16_t &holdingRegister) {
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_HOLDING_REGISTER, address, 1);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
uint8_t response[11]; // Expected response size for reading 1 register
|
|
if (!receiveResponse(response, 11)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure function code matches the request
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_HOLDING_REGISTER)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_HOLDING_REGISTER), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Extract holding register value (Big-endian format)
|
|
holdingRegister = (response[9] << 8) | response[10];
|
|
return ModbusError::NONE; // Success
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readMultipleHoldingRegisters(int address, int count, uint16_t holdingRegisters[]) {
|
|
if (count < 1 || count > 125) { // MODBUS limits reading up to 125 registers per request
|
|
printf("MODBUS_TCP_CLIENT: Invalid holding register count (1-125 allowed)\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_HOLDING_REGISTER, address, count);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
// Expected response size: 9-byte header + 2 * count registers
|
|
int expectedSize = 9 + (count * 2);
|
|
uint8_t response[256]; // Ensure buffer is large enough
|
|
|
|
if (!receiveResponse(response, expectedSize)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure function code matches the request
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_HOLDING_REGISTER)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_HOLDING_REGISTER), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Extract register values (each register is 2 bytes, big-endian)
|
|
for (int i = 0; i < count; i++) {
|
|
holdingRegisters[i] = (response[9 + (i * 2)] << 8) | response[10 + (i * 2)];
|
|
}
|
|
|
|
return ModbusError::NONE;
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readInputRegister(int address, uint16_t &inputRegister) {
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_INPUT_REGISTER, address, 1);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
uint8_t response[11]; // Expected response size for reading 1 register
|
|
if (!receiveResponse(response, 11)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure function code matches the request
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_INPUT_REGISTER)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_INPUT_REGISTER), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Extract input register value (Big-endian format)
|
|
inputRegister = (response[9] << 8) | response[10];
|
|
return ModbusError::NONE; // Success
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readMultipleInputRegisters(int address, int count, uint16_t inputRegisters[]) {
|
|
if (count < 1 || count > 125) { // MODBUS limits reading up to 125 registers per request
|
|
printf("MODBUS_TCP_CLIENT: Invalid input register count (1-125 allowed)\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
uint8_t request[12];
|
|
buildReadRequest(request, ModbusFunction::READ_INPUT_REGISTER, address, count);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
// Expected response size: 9-byte header + 2 * count registers
|
|
int expectedSize = 9 + (count * 2);
|
|
uint8_t response[256]; // Ensure buffer is large enough
|
|
|
|
if (!receiveResponse(response, expectedSize)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Handle MODBUS exception responses (0x80 + function code)
|
|
if (response[7] & 0x80) {
|
|
printf("MODBUS_TCP_CLIENT: MODBUS Exception Code %02X\n", response[8]);
|
|
return ModbusError::EXCEPTION_RESPONSE;
|
|
}
|
|
|
|
// Ensure function code matches the request
|
|
if (response[7] != static_cast<uint8_t>(ModbusFunction::READ_INPUT_REGISTER)) {
|
|
printf("MODBUS_TCP_CLIENT: Warning: Unexpected function code (Expected: %02X, Got: %02X)\n",
|
|
static_cast<uint8_t>(ModbusFunction::READ_INPUT_REGISTER), response[7]);
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
// Extract register values (each register is 2 bytes, big-endian)
|
|
for (int i = 0; i < count; i++) {
|
|
inputRegisters[i] = (response[9 + (i * 2)] << 8) | response[10 + (i * 2)];
|
|
}
|
|
|
|
return ModbusError::NONE;
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::writeCoil(int address, bool value) {
|
|
uint8_t request[12];
|
|
buildWriteSingleRequest(request, ModbusFunction::WRITE_SINGLE_COIL, address, value ? 0xFF00 : 0x0000);
|
|
sendRequest(request, 12);
|
|
|
|
// Receive response
|
|
uint8_t response[12];
|
|
if (!receiveResponse(response, 12)) {
|
|
return ModbusError::TIMEOUT; // No response received
|
|
}
|
|
|
|
// Check if response matches request (MODBUS TCP should echo back the same request)
|
|
for (int i = 0; i < 12; i++) {
|
|
if (request[i] != response[i]) {
|
|
printf("MODBUS_TCP_CLIENT: Response does not match request!\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
}
|
|
|
|
return ModbusError::NONE; // Success
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::writeMultipleCoils(int address, int count, const bool values[]) {
|
|
if (count < 1 || count > 1968) { // MODBUS limit: max 1968 coils per request
|
|
printf("MODBUS_TCP_CLIENT: Invalid coil count (1-1968 allowed)\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
int byteCount = (count + 7) / 8; // Each byte holds 8 coils
|
|
uint8_t coilData[byteCount];
|
|
|
|
// Initialize to 0 (since we may not use all bits)
|
|
for (int i = 0; i < byteCount; i++) {
|
|
coilData[i] = 0;
|
|
}
|
|
|
|
// Pack coil data into bytes
|
|
for (int i = 0; i < count; i++) {
|
|
if (values[i]) {
|
|
coilData[i / 8] |= (1 << (i % 8));
|
|
}
|
|
}
|
|
|
|
uint8_t request[13 + byteCount];
|
|
buildWriteMultipleRequest(request, ModbusFunction::WRITE_MULTIPLE_COILS, address, count, coilData, byteCount);
|
|
|
|
sendRequest(request, 13 + byteCount);
|
|
|
|
// The expected response is always **12 bytes**
|
|
uint8_t response[12];
|
|
if (!receiveResponse(response, 12)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Ensure the response matches the **first 10 bytes**, except for byte 5 (message length byte)
|
|
for (int i = 0; i < 10; i++) {
|
|
if (i == 5) continue; // Skip byte 5 (message length field)
|
|
|
|
if (request[i] != response[i]) {
|
|
printf("MODBUS_TCP_CLIENT: Response does not match request!\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
}
|
|
|
|
return ModbusError::NONE; // Success
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::writeHoldingRegister(int address, uint16_t value) {
|
|
uint8_t request[12];
|
|
buildWriteSingleRequest(request, ModbusFunction::WRITE_SINGLE_HOLDING_REGISTER, address, value);
|
|
|
|
sendRequest(request, 12);
|
|
|
|
// Expected response size = 12 bytes (full echo of the request)
|
|
uint8_t response[12];
|
|
if (!receiveResponse(response, 12)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Ensure response matches request exactly (full 12 bytes)
|
|
for (int i = 0; i < 12; i++) {
|
|
if (request[i] != response[i]) {
|
|
printf("MODBUS_TCP_CLIENT: Response does not match request!\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
}
|
|
|
|
return ModbusError::NONE; // Success
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::writeMultipleHoldingRegisters(int address, int count, const uint16_t values[]) {
|
|
if (count < 1 || count > 123) { // MODBUS limit: max 123 registers per request
|
|
printf("MODBUS_TCP_CLIENT: Invalid register count (1-123 allowed)\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
|
|
int byteCount = count * 2; // Each register is 2 bytes
|
|
uint8_t registerData[byteCount];
|
|
|
|
// Convert register values to byte array (big-endian format)
|
|
for (int i = 0; i < count; i++) {
|
|
registerData[i * 2] = values[i] >> 8; // High byte
|
|
registerData[i * 2 + 1] = values[i] & 0xFF; // Low byte
|
|
}
|
|
|
|
uint8_t request[13 + byteCount];
|
|
buildWriteMultipleRequest(request, ModbusFunction::WRITE_MULTIPLE_HOLDING_REGISTERS, address, count, registerData, byteCount);
|
|
|
|
sendRequest(request, 13 + byteCount);
|
|
|
|
// Expected response size = 12 bytes (first 10 bytes + 2 bytes for number of registers written)
|
|
uint8_t response[12];
|
|
if (!receiveResponse(response, 12)) {
|
|
return ModbusError::TIMEOUT;
|
|
}
|
|
|
|
// Ensure response matches request (except for byte 5)
|
|
for (int i = 0; i < 10; i++) {
|
|
if (i == 5) continue; // Skip byte 5 (message length field)
|
|
|
|
if (request[i] != response[i]) {
|
|
printf("MODBUS_TCP_CLIENT: Response does not match request!\n");
|
|
return ModbusError::INVALID_RESPONSE;
|
|
}
|
|
}
|
|
|
|
return ModbusError::NONE; // Success
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::readAll() {
|
|
/*
|
|
Reads every coil, discrete input, input register, and holding register
|
|
assuming that they start at address 0
|
|
*/
|
|
|
|
if (coilsRead == nullptr && discreteInputs == nullptr &&
|
|
inputRegisters == nullptr && holdingRegistersRead == nullptr) {
|
|
printf("MODBUS_TCP_CLIENT: readAll() called, but wrong constructor was used.\n");
|
|
return ModbusError::INVALID_REQUEST;
|
|
}
|
|
|
|
ModbusError error = ModbusError::NONE;
|
|
if (coilsRead != nullptr) {
|
|
error = readMultipleCoils(startCoils, numCoils, coilsRead);
|
|
if (error != ModbusError::NONE) return error;
|
|
}
|
|
|
|
if (discreteInputs != nullptr) {
|
|
error = readMultipleDiscreteInputs(startDiscreteInputs, numDiscreteInputs, discreteInputs);
|
|
if (error != ModbusError::NONE) return error;
|
|
}
|
|
|
|
if (inputRegisters != nullptr) {
|
|
error = readMultipleInputRegisters(startInputRegisters, numInputRegisters, inputRegisters);
|
|
if (error != ModbusError::NONE) return error;
|
|
}
|
|
|
|
if (holdingRegistersRead != nullptr) {
|
|
error = readMultipleHoldingRegisters(startHoldingRegisters, numHoldingRegisters, holdingRegistersRead);
|
|
|
|
}
|
|
return error;
|
|
}
|
|
|
|
ModbusError ModbusTCPClient::writeAll() {
|
|
/*
|
|
Reads every coil and holding register assuming that they start at address 0
|
|
*/
|
|
if (coilsWrite == nullptr && holdingRegistersWrite) {
|
|
printf("MODBUS_TCP_CLIENT: writeAll() called, but wrong constructor was used.\n");
|
|
return ModbusError::INVALID_REQUEST;
|
|
}
|
|
|
|
ModbusError error = ModbusError::NONE;
|
|
if (coilsWrite != nullptr) {
|
|
error = writeMultipleCoils(startCoils, numCoils, coilsWrite);
|
|
if (error != ModbusError::NONE) return error;
|
|
}
|
|
|
|
if (holdingRegistersWrite != nullptr) {
|
|
error = writeMultipleHoldingRegisters(startHoldingRegisters, numHoldingRegisters, holdingRegistersWrite);
|
|
}
|
|
|
|
return error;
|
|
}
|
|
|
|
|
|
// Setters for writing values (preferred to be used)
|
|
void ModbusTCPClient::setCoil(int address, bool value) {
|
|
if (address >= 0 && address < numCoils) {
|
|
coilsWrite[address] = value;
|
|
}
|
|
}
|
|
|
|
void ModbusTCPClient::setHoldingRegister(int address, uint16_t value) {
|
|
if (address >= 0 && address < numHoldingRegisters) {
|
|
holdingRegistersWrite[address] = value;
|
|
}
|
|
}
|
|
|
|
// Getters (preferred to be used as long as readAll is being called)
|
|
bool ModbusTCPClient::getCoil(int address) const {
|
|
return (address >= 0 && address < numCoils) ? coilsRead[address] : false;
|
|
}
|
|
|
|
bool ModbusTCPClient::getDesiredCoil(int address) const {
|
|
return (address >= 0 && address < numCoils) ? coilsWrite[address] : false;
|
|
}
|
|
|
|
bool ModbusTCPClient::getDiscreteInput(int address) const {
|
|
return (address >= 0 && address < numDiscreteInputs) ? discreteInputs[address] : false;
|
|
}
|
|
|
|
uint16_t ModbusTCPClient::getHoldingRegister(int address) const {
|
|
return (address >= 0 && address < numHoldingRegisters) ? holdingRegistersRead[address] : 0;
|
|
}
|
|
|
|
uint16_t ModbusTCPClient::getDesiredHoldingRegister(int address) const {
|
|
return (address >= 0 && address < numHoldingRegisters) ? holdingRegistersWrite[address] : 0;
|
|
}
|
|
|
|
uint16_t ModbusTCPClient::getInputRegister(int address) const {
|
|
return (address >= 0 && address < numInputRegisters) ? inputRegisters[address] : 0;
|
|
} |