Ich habe mir ein kleines Programm in C, basierend auf der modbuslib geschrieben.
Es horcht am Port 1502 und bekommt den aktuellen Überschuss in Klartext als 5-stellige Zahl.
Soll es da die Zahlen in einem andern Format bekommen(z.b. MQTT) müsste man das anpassen oder ein anderes Skript vorschalten.
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#include <pthread.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include "/usr/include/modbus/modbus.h"
#define DEFAULT_BUFLEN 512
#define DEFAULT_PORT 1502
modbus_mapping_t *mapping;
int n_shutdown;
void *ModbusThread(void *lpParam)
{
uint8_t req[MODBUS_RTU_MAX_ADU_LENGTH];// request buffer
int len;// length of the request/response
int nStop;
mapping = modbus_mapping_new(0, 0, 52, 0);
if (!mapping) {
printf("Failed to allocate the mapping: %s\n", modbus_strerror(errno));
exit(1);
}
mapping->tab_registers[0] = 10; //Firmware
mapping->tab_registers[21] = 0; //Comm ok
mapping->tab_registers[24] = 0; //Metering ok
mapping->tab_registers[27] = 0; //Counter 1 Total high (in 10 Wh)
mapping->tab_registers[28] = 0; //Counter 1 Total low (in 10 Wh)
mapping->tab_registers[29] = 0; //Counter 1 Partial high (in 10 Wh)
mapping->tab_registers[30] = 0; //Counter 1 Partial low (in 10 Wh)
mapping->tab_registers[31] = 0; //Counter 2 Total high (in 10 Wh)
mapping->tab_registers[32] = 0; //Counter 2 Total low (in 10 Wh)
mapping->tab_registers[33] = 0; //Counter 2 Partial high (in 10 Wh)
mapping->tab_registers[34] = 0; //Counter 2 Partial low (in 10 Wh)
mapping->tab_registers[37] = 0; //Power Phase 1 (in 10W)
mapping->tab_registers[42] = 0; //Power Phase 2 (in 10W)
mapping->tab_registers[47] = 0; //Power Phase 3 (in 10W)
modbus_t *ctx = modbus_new_rtu("/dev/ttyUSB0", 19200, 'E', 8, 1);
if (!ctx) {
printf("Failed to create the context: %s\n", modbus_strerror(errno));
exit(1);
}
//Set the Modbus address of this slave (to 3)
modbus_set_slave(ctx, 60);
if (modbus_connect(ctx) == -1) {
printf("Unable to connect: %s\n", modbus_strerror(errno));
modbus_free(ctx);
exit(1);
}
nStop = 0;
while ((nStop == 0) && (n_shutdown == 0)) {
len = modbus_receive(ctx, req);
if (len == -1)
{
printf("Error on receive: %s\n", modbus_strerror(errno));
nStop = 1;
}
else {
//printf("Receive Length: %d\n", len);
len = modbus_reply(ctx, req, len, mapping);
}
}
printf("\nExit the loop: %s\n", modbus_strerror(errno));
modbus_mapping_free(mapping);
modbus_close(ctx);
modbus_free(ctx);
return 0;
}
void *SocketThread(void *lpParam)
{
int sockfd, newsockfd, portno;
socklen_t clilen;
char buffer[DEFAULT_BUFLEN];
struct sockaddr_in serv_addr, cli_addr;
int n;
unsigned int iPower;
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
printf("ERROR opening socket");
n_shutdown = 1;
return 0;
}
bzero((char *) &serv_addr, sizeof(serv_addr));
portno = DEFAULT_PORT;
serv_addr.sin_family = AF_INET;
serv_addr.sin_addr.s_addr = INADDR_ANY;
serv_addr.sin_port = htons(portno);
if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
{
printf("%d - ", errno);
printf("ERROR on binding");
close(sockfd);
n_shutdown = 1;
return 0;
}
while (n_shutdown == 0)
{
listen(sockfd,5);
clilen = sizeof(cli_addr);
newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
if (newsockfd < 0)
{
printf("ERROR on accept");
close(sockfd);
n_shutdown = 1;
return 0;
}
bzero(buffer,DEFAULT_BUFLEN);
n = read(newsockfd,buffer,DEFAULT_BUFLEN-1);
if (n < 0)
{
printf("ERROR reading from socket");
close(newsockfd);
close(sockfd);
n_shutdown = 1;
return 0;
}
if(n == 5)
{
iPower = atoi(buffer);
printf("\nPower: %u W", iPower);
mapping->tab_registers[37] = iPower / 30; //Power Phase 1 (in 10W)
mapping->tab_registers[42] = iPower / 30; //Power Phase 2 (in 10W)
mapping->tab_registers[47] = iPower / 30; //Power Phase 3 (in 10W)
}
close(newsockfd);
}
close(sockfd);
n_shutdown = 1;
return 0;
}
int main()
{
pthread_t threadSer;
pthread_t threadSock;
n_shutdown = 0;
pthread_create( &threadSock, NULL, SocketThread, NULL);
while(n_shutdown == 0)
{
pthread_create( &threadSer, NULL, ModbusThread, NULL);
pthread_join( threadSer, NULL);
}
pthread_join( threadSock, NULL);
return 0;
}
). Demenstprechend sollte eine Implementierung auf einem Raspberry Pi auch kein Hexenwerk sein.