IGH的EtherCAT通信的实时通信例程，直接编写Makefile来实现编译

#include "TestIGH.h" /*****************************************************************************/ void check_domain_state(void) { ec_domain_state_t ds; ecrt_domain_state(domain, &ds); if (ds.working_counter != domain_state.working_counter) { printf("Domain: Working Counter changed to %u.\n", ds.working_counter); } if (ds.wc_state != domain_state.wc_state) { printf("Domain: Working Counter State changed to %u.\n", ds.wc_state); } domain_state = ds; } /****************************************************************************/ struct period_info { struct timespec next_period; long period_ns; }; /****************************************************************************/ static void inc_period(struct period_info *pinfo) { pinfo->next_period.tv_nsec += pinfo->period_ns; while (pinfo->next_period.tv_nsec >= 1000000000) { /* timespec nsec overflow */ pinfo->next_period.tv_sec++; pinfo->next_period.tv_nsec -= 1000000000; } } /****************************************************************************/ static void periodic_task_init(struct period_info *pinfo) { /* for simplicity, hardcoding a 100 ms period */ pinfo->period_ns = 100000000; /* find timestamp to first run */ clock_gettime(CLOCK_MONOTONIC, &(pinfo->next_period)); } /****************************************************************************/ static void do_rt_task() { // receive process data ecrt_master_receive(master); ecrt_domain_process(domain); // check process data state check_domain_state(); // read process data int16_t raw_value = EC_READ_S16(domain_pd + off_ana_in); cycle_counter++; if (cycle_counter % 10 == 0) { printf("AnaIn: Value %5i ~ %.3f V\n", raw_value, raw_value * 10.0 / 32768.0); } // send process data ecrt_domain_queue(domain); ecrt_master_send(master); } /****************************************************************************/ static void wait_rest_of_period(struct period_info *pinfo) { inc_period(pinfo); /* for simplicity, ignoring possibilities of signal wakes */ clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &pinfo->next_period, NULL); } /****************************************************************************/ void *simple_cyclic_task(void *data) { printf("Started cyclic thread.\n"); struct period_info pinfo; periodic_task_init(&pinfo); while (1) { do_rt_task(); wait_rest_of_period(&pinfo); } return NULL; } /****************************************************************************/ int init_ethercat() { ec_slave_config_t *sc; master = ecrt_request_master(0); if (!master) { return -1; } domain = ecrt_master_create_domain(master); if (!domain) { return -1; } if (!(sc = ecrt_master_slave_config(master, AnaInSlavePos, Beckhoff_EL3104))) { fprintf(stderr, "Failed to get slave configuration.\n"); return -1; } printf("Configuring PDOs...\n"); if (ecrt_slave_config_pdos(sc, EC_END, el3104_syncs)) { fprintf(stderr, "Failed to configure PDOs.\n"); return -1; } // Register PDOs for exchange if (ecrt_domain_reg_pdo_entry_list(domain, domain_regs)) { fprintf(stderr, "PDO entry registration failed!\n"); return -1; } printf("Activating master...\n"); if (ecrt_master_activate(master)) { return -1; } if (!(domain_pd = ecrt_domain_data(domain))) { return -1; } return 0; } /****************************************************************************/ int main(int argc, char* argv[]) { struct sched_param param; pthread_attr_t attr; pthread_t thread; int ret; ret = init_ethercat(); if (ret) { printf("Failed to init EtherCAT master.\n"); exit(-2); } /* Lock memory */ if (mlockall(MCL_CURRENT | MCL_FUTURE) == -1) { printf("mlockall() failed: %m\n"); exit(-2); } /* Initialize pthread attributes (default values) */ ret = pthread_attr_init(&attr); if (ret) { printf("init pthread attributes failed\n"); goto out; } /* Set a specific stack size */ ret = pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN + MY_STACK_SIZE); if (ret) { printf("pthread setstacksize failed\n"); goto out; } /* Set scheduler policy and priority of pthread */ ret = pthread_attr_setschedpolicy(&attr, SCHED_FIFO); if (ret) { printf("pthread setschedpolicy failed\n"); goto out; } param.sched_priority = 80; ret = pthread_attr_setschedparam(&attr, &param); if (ret) { printf("pthread setschedparam failed\n"); goto out; } /* Use scheduling parameters of attr */ ret = pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED); if (ret) { printf("pthread setinheritsched failed\n"); goto out; } /* Create a pthread with specified attributes */ ret = pthread_create(&thread, &attr, simple_cyclic_task, NULL); if (ret) { printf("create pthread failed: %s\n", strerror(ret)); goto out; } ret = pthread_setname_np(thread, "ethercat-rt"); if (ret) { printf("failed to set thread name\n"); } /* Join the thread and wait until it is done */ ret = pthread_join(thread, NULL); if (ret) { printf("join pthread failed: %m\n"); } out: return ret; } /****************************************************************************/