1 /******************************************************************************

     2  *

     3  *  $Id$

     4  *

     5  *  Copyright (C)      2011  IgH Andreas Stewering-Bone

     6  *                     2012  Florian Pose <fp@igh-essen.com>

     7  *

     8  *  This file is part of the IgH EtherCAT master

     9  *

    10  *  The IgH EtherCAT Master is free software; you can redistribute it and/or

    11  *  modify it under the terms of the GNU General Public License version 2, as

    12  *  published by the Free Software Foundation.

    13  *

    14  *  The IgH EtherCAT master is distributed in the hope that it will be useful,

    15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of

    16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General

    17  *  Public License for more details.

    18  *

    19  *  You should have received a copy of the GNU General Public License along

    20  *  with the IgH EtherCAT master. If not, see <http://www.gnu.org/licenses/>.

    21  *

    22  *  ---

    23  *

    24  *  The license mentioned above concerns the source code only. Using the

    25  *  EtherCAT technology and brand is only permitted in compliance with the

    26  *  industrial property and similar rights of Beckhoff Automation GmbH.

    27  *

    28  *****************************************************************************/

    29 

    30 #include <sched.h>

    31 #include <stdio.h>

    32 #include <stdlib.h>

    33 #include <fcntl.h>

    34 #include <signal.h>

    35 

    36 #include <rtai_lxrt.h>

    37 #include <rtdm/rtdm.h>

    38 

    39 #include "ecrt.h"

    40 

    41 #define rt_printf(X, Y)

    42 

    43 #define NSEC_PER_SEC 1000000000

    44 

    45 RT_TASK *task;

    46 

    47 static unsigned int cycle_ns = 1000000; /* 1 ms */

    48 

    49 static int run = 1;

    50 

    51 /****************************************************************************/

    52 

    53 // EtherCAT

    54 static ec_master_t *master = NULL;

    55 static ec_master_state_t master_state = {};

    56 

    57 static ec_domain_t *domain1 = NULL;

    58 static ec_domain_state_t domain1_state = {};

    59 

    60 static uint8_t *domain1_pd = NULL;

    61 

    62 static ec_slave_config_t *sc_dig_out_01 = NULL;

    63 

    64 /****************************************************************************/

    65 

    66 // EtherCAT distributed clock variables

    67 

    68 #define DC_FILTER_CNT          1024

    69 #define SYNC_MASTER_TO_REF        1

    70 

    71 static uint64_t dc_start_time_ns = 0LL;

    72 static uint64_t dc_time_ns = 0;

    73 #if SYNC_MASTER_TO_REF

    74 static uint8_t  dc_started = 0;

    75 static int32_t  dc_diff_ns = 0;

    76 static int32_t  prev_dc_diff_ns = 0;

    77 static int64_t  dc_diff_total_ns = 0LL;

    78 static int64_t  dc_delta_total_ns = 0LL;

    79 static int      dc_filter_idx = 0;

    80 static int64_t  dc_adjust_ns;

    81 #endif

    82 static int64_t  system_time_base = 0LL;

    83 static uint64_t wakeup_time = 0LL;

    84 static uint64_t overruns = 0LL;

    85 

    86 /****************************************************************************/

    87 

    88 // process data

    89 

    90 #define BusCoupler01_Pos  0, 0

    91 #define DigOutSlave01_Pos 0, 1

    92 

    93 #define Beckhoff_EK1100 0x00000002, 0x044c2c52

    94 #define Beckhoff_EL2004 0x00000002, 0x07d43052

    95 

    96 // offsets for PDO entries

    97 static unsigned int off_dig_out0 = 0;

    98 

    99 // process data

   100 

   101 const static ec_pdo_entry_reg_t domain1_regs[] = {

   102    {DigOutSlave01_Pos, Beckhoff_EL2004, 0x7000, 0x01, &off_dig_out0, NULL},

   103    {}

   104 };

   105 

   106 /****************************************************************************/

   107 

   108 /* Slave 1, "EL2004"

   109  * Vendor ID:       0x00000002

   110  * Product code:    0x07d43052

   111  * Revision number: 0x00100000

   112  */

   113 

   114 ec_pdo_entry_info_t slave_1_pdo_entries[] = {

   115    {0x7000, 0x01, 1}, /* Output */

   116    {0x7010, 0x01, 1}, /* Output */

   117    {0x7020, 0x01, 1}, /* Output */

   118    {0x7030, 0x01, 1}, /* Output */

   119 };

   120 

   121 ec_pdo_info_t slave_1_pdos[] = {

   122    {0x1600, 1, slave_1_pdo_entries + 0}, /* Channel 1 */

   123    {0x1601, 1, slave_1_pdo_entries + 1}, /* Channel 2 */

   124    {0x1602, 1, slave_1_pdo_entries + 2}, /* Channel 3 */

   125    {0x1603, 1, slave_1_pdo_entries + 3}, /* Channel 4 */

   126 };

   127 

   128 ec_sync_info_t slave_1_syncs[] = {

   129    {0, EC_DIR_OUTPUT, 4, slave_1_pdos + 0, EC_WD_ENABLE},

   130    {0xff}

   131 };

   132 

   133 /*****************************************************************************

   134  * Realtime task

   135  ****************************************************************************/

   136 

   137 /** Get the time in ns for the current cpu, adjusted by system_time_base.

   138  *

   139  * \attention Rather than calling rt_get_time_ns() directly, all application

   140  * time calls should use this method instead.

   141  *

   142  * \ret The time in ns.

   143  */

   144 uint64_t system_time_ns(void)

   145 {

   146     RTIME time = rt_get_time_ns();

   147 

   148     if (system_time_base > time) {

   149         rt_printk("%s() error: system_time_base greater than"

   150                 " system time (system_time_base: %lld, time: %llu\n",

   151                 __func__, system_time_base, time);

   152         return time;

   153     }

   154     else {

   155         return time - system_time_base;

   156     }

   157 }

   158 

   159 /****************************************************************************/

   160 

   161 /** Convert system time to RTAI time in counts (via the system_time_base).

   162  */

   163 RTIME system2count(

   164         uint64_t time

   165         )

   166 {

   167     RTIME ret;

   168 

   169     if ((system_time_base < 0) &&

   170             ((uint64_t) (-system_time_base) > time)) {

   171         rt_printk("%s() error: system_time_base less than"

   172                 " system time (system_time_base: %lld, time: %llu\n",

   173                 __func__, system_time_base, time);

   174         ret = time;

   175     }

   176     else {

   177         ret = time + system_time_base;

   178     }

   179 

   180     return nano2count(ret);

   181 }

   182 

   183 /*****************************************************************************/

   184 

   185 /** Synchronise the distributed clocks

   186  */

   187 void sync_distributed_clocks(void)

   188 {

   189 #if SYNC_MASTER_TO_REF

   190     uint32_t ref_time = 0;

   191     uint64_t prev_app_time = dc_time_ns;

   192 #endif

   193 

   194     dc_time_ns = system_time_ns();

   195 

   196     // set master time in nano-seconds

   197     ecrt_master_application_time(master, dc_time_ns);

   198 

   199 #if SYNC_MASTER_TO_REF

   200     // get reference clock time to synchronize master cycle

   201     ecrt_master_reference_clock_time(master, &ref_time);

   202     dc_diff_ns = (uint32_t) prev_app_time - ref_time;

   203 #else

   204     // sync reference clock to master

   205     ecrt_master_sync_reference_clock(master);

   206 #endif

   207 

   208     // call to sync slaves to ref slave

   209     ecrt_master_sync_slave_clocks(master);

   210 }

   211 

   212 /*****************************************************************************/

   213 

   214 /** Return the sign of a number

   215  *

   216  * ie -1 for -ve value, 0 for 0, +1 for +ve value

   217  *

   218  * \retval the sign of the value

   219  */

   220 #define sign(val) \

   221     ({ typeof (val) _val = (val); \

   222     ((_val > 0) - (_val < 0)); })

   223 

   224 /*****************************************************************************/

   225 

   226 /** Update the master time based on ref slaves time diff

   227  *

   228  * called after the ethercat frame is sent to avoid time jitter in

   229  * sync_distributed_clocks()

   230  */

   231 void update_master_clock(void)

   232 {

   233 #if SYNC_MASTER_TO_REF

   234     // calc drift (via un-normalised time diff)

   235     int32_t delta = dc_diff_ns - prev_dc_diff_ns;

   236     prev_dc_diff_ns = dc_diff_ns;

   237 

   238     // normalise the time diff

   239     dc_diff_ns =

   240         ((dc_diff_ns + (cycle_ns / 2)) % cycle_ns) - (cycle_ns / 2);

   241 

   242     // only update if primary master

   243     if (dc_started) {

   244 

   245         // add to totals

   246         dc_diff_total_ns += dc_diff_ns;

   247         dc_delta_total_ns += delta;

   248         dc_filter_idx++;

   249 

   250         if (dc_filter_idx >= DC_FILTER_CNT) {

   251             // add rounded delta average

   252             dc_adjust_ns +=

   253                 ((dc_delta_total_ns + (DC_FILTER_CNT / 2)) / DC_FILTER_CNT);

   254 

   255             // and add adjustment for general diff (to pull in drift)

   256             dc_adjust_ns += sign(dc_diff_total_ns / DC_FILTER_CNT);

   257 

   258             // limit crazy numbers (0.1% of std cycle time)

   259             if (dc_adjust_ns < -1000) {

   260                 dc_adjust_ns = -1000;

   261             }

   262             if (dc_adjust_ns > 1000) {

   263                 dc_adjust_ns =  1000;

   264             }

   265 

   266             // reset

   267             dc_diff_total_ns = 0LL;

   268             dc_delta_total_ns = 0LL;

   269             dc_filter_idx = 0;

   270         }

   271 

   272         // add cycles adjustment to time base (including a spot adjustment)

   273         system_time_base += dc_adjust_ns + sign(dc_diff_ns);

   274     }

   275     else {

   276         dc_started = (dc_diff_ns != 0);

   277 

   278         if (dc_started) {

   279             // output first diff

   280             rt_printk("First master diff: %d.\n", dc_diff_ns);

   281 

   282             // record the time of this initial cycle

   283             dc_start_time_ns = dc_time_ns;

   284         }

   285     }

   286 #endif

   287 }

   288 

   289 /****************************************************************************/

   290 

   291 void rt_check_domain_state(void)

   292 {

   293     ec_domain_state_t ds = {};

   294 

   295     ecrt_domain_state(domain1, &ds);

   296 

   297     if (ds.working_counter != domain1_state.working_counter) {

   298         rt_printf("Domain1: WC %u.\n", ds.working_counter);

   299     }

   300 

   301     if (ds.wc_state != domain1_state.wc_state) {

   302         rt_printf("Domain1: State %u.\n", ds.wc_state);

   303     }

   304 

   305     domain1_state = ds;

   306 }

   307 

   308 /****************************************************************************/

   309 

   310 void rt_check_master_state(void)

   311 {

   312     ec_master_state_t ms;

   313 

   314     ecrt_master_state(master, &ms);

   315 

   316     if (ms.slaves_responding != master_state.slaves_responding) {

   317         rt_printf("%u slave(s).\n", ms.slaves_responding);

   318     }

   319 

   320     if (ms.al_states != master_state.al_states) {

   321         rt_printf("AL states: 0x%02X.\n", ms.al_states);

   322     }

   323 

   324     if (ms.link_up != master_state.link_up) {

   325         rt_printf("Link is %s.\n", ms.link_up ? "up" : "down");

   326     }

   327 

   328     master_state = ms;

   329 }

   330 

   331 /****************************************************************************/

   332 

   333 /** Wait for the next period

   334  */

   335 void wait_period(void)

   336 {

   337     while (1)

   338     {

   339         RTIME wakeup_count = system2count(wakeup_time);

   340         RTIME current_count = rt_get_time();

   341 

   342         if ((wakeup_count < current_count)

   343                 || (wakeup_count > current_count + (50 * cycle_ns))) {

   344             rt_printk("%s(): unexpected wake time!\n", __func__);

   345         }

   346 

   347         switch (rt_sleep_until(wakeup_count)) {

   348             case RTE_UNBLKD:

   349                 rt_printk("rt_sleep_until(): RTE_UNBLKD\n");

   350                 continue;

   351 

   352             case RTE_TMROVRN:

   353                 rt_printk("rt_sleep_until(): RTE_TMROVRN\n");

   354                 overruns++;

   355 

   356                 if (overruns % 100 == 0) {

   357                     // in case wake time is broken ensure other processes get

   358                     // some time slice (and error messages can get displayed)

   359                     rt_sleep(cycle_ns / 100);

   360                 }

   361                 break;

   362 

   363             default:

   364                 break;

   365         }

   366 

   367         // done if we got to here

   368         break;

   369     }

   370 

   371     // calc next wake time (in sys time)

   372     wakeup_time += cycle_ns;

   373 }

   374 

   375 /****************************************************************************/

   376 

   377 void my_cyclic(void)

   378 {

   379     int cycle_counter = 0;

   380     unsigned int blink = 0;

   381 

   382     // oneshot mode to allow adjustable wake time

   383     rt_set_oneshot_mode();

   384 

   385     // set first wake time in a few cycles

   386     wakeup_time = system_time_ns() + 10 * cycle_ns;

   387 

   388     // start the timer

   389     start_rt_timer(nano2count(cycle_ns));

   390 

   391     rt_make_hard_real_time();

   392 

   393     while (run) {

   394         // wait for next period (using adjustable system time)

   395         wait_period();

   396 

   397         cycle_counter++;

   398 

   399         if (!run) {

   400             break;

   401         }

   402 

   403         // receive EtherCAT

   404         ecrt_master_receive(master);

   405         ecrt_domain_process(domain1);

   406 

   407         rt_check_domain_state();

   408 

   409         if (!(cycle_counter % 1000)) {

   410             rt_check_master_state();

   411         }

   412 

   413         if (!(cycle_counter % 200)) {

   414             blink = !blink;

   415         }

   416 

   417         EC_WRITE_U8(domain1_pd + off_dig_out0, blink ? 0x00 : 0x0F);

   418 

   419         // queue process data

   420         ecrt_domain_queue(domain1);

   421 

   422         // sync distributed clock just before master_send to set

   423         // most accurate master clock time

   424         sync_distributed_clocks();

   425 

   426         // send EtherCAT data

   427         ecrt_master_send(master);

   428 

   429         // update the master clock

   430         // Note: called after ecrt_master_send() to reduce time

   431         // jitter in the sync_distributed_clocks() call

   432         update_master_clock();

   433     }

   434 

   435     rt_make_soft_real_time();

   436     stop_rt_timer();

   437 }

   438 

   439 /****************************************************************************

   440  * Signal handler

   441  ***************************************************************************/

   442 

   443 void signal_handler(int sig)

   444 {

   445     run = 0;

   446 }

   447 

   448 /****************************************************************************

   449  * Main function

   450  ***************************************************************************/

   451 

   452 int main(int argc, char *argv[])

   453 {

   454     ec_slave_config_t *sc_ek1100;

   455     int ret;

   456 

   457     signal(SIGTERM, signal_handler);

   458     signal(SIGINT, signal_handler);

   459 

   460     mlockall(MCL_CURRENT | MCL_FUTURE);

   461 

   462     printf("Requesting master...\n");

   463     master = ecrt_request_master(0);

   464     if (!master) {

   465         return -1;

   466     }

   467 

   468     domain1 = ecrt_master_create_domain(master);

   469     if (!domain1) {

   470         return -1;

   471     }

   472 

   473     printf("Creating slave configurations...\n");

   474 

   475     // Create configuration for bus coupler

   476     sc_ek1100 =

   477         ecrt_master_slave_config(master, BusCoupler01_Pos, Beckhoff_EK1100);

   478     if (!sc_ek1100) {

   479         return -1;

   480     }

   481 

   482     sc_dig_out_01 =

   483         ecrt_master_slave_config(master, DigOutSlave01_Pos, Beckhoff_EL2004);

   484     if (!sc_dig_out_01) {

   485         fprintf(stderr, "Failed to get slave configuration.\n");

   486         return -1;

   487     }

   488 

   489     if (ecrt_slave_config_pdos(sc_dig_out_01, EC_END, slave_1_syncs)) {

   490         fprintf(stderr, "Failed to configure PDOs.\n");

   491         return -1;

   492     }

   493 

   494     if (ecrt_domain_reg_pdo_entry_list(domain1, domain1_regs)) {

   495         fprintf(stderr, "PDO entry registration failed!\n");

   496         return -1;

   497     }

   498 

   499     /* Set the initial master time and select a slave to use as the DC

   500      * reference clock, otherwise pass NULL to auto select the first capable

   501      * slave. Note: This can be used whether the master or the ref slave will

   502      * be used as the systems master DC clock.

   503      */

   504     dc_start_time_ns = system_time_ns();

   505     dc_time_ns = dc_start_time_ns;

   506     ecrt_master_application_time(master, dc_start_time_ns);

   507 

   508     ret = ecrt_master_select_reference_clock(master, sc_ek1100);

   509     if (ret < 0) {

   510         fprintf(stderr, "Failed to select reference clock: %s\n",

   511                 strerror(-ret));

   512         return ret;

   513     }

   514 

   515     printf("Activating master...\n");

   516     if (ecrt_master_activate(master)) {

   517         return -1;

   518     }

   519 

   520     if (!(domain1_pd = ecrt_domain_data(domain1))) {

   521         fprintf(stderr, "Failed to get domain data pointer.\n");

   522         return -1;

   523     }

   524 

   525     /* Create cyclic RT-thread */

   526     struct sched_param param;

   527     param.sched_priority = sched_get_priority_max(SCHED_FIFO) - 1;

   528     if (sched_setscheduler(0, SCHED_FIFO, &param) == -1) {

   529         puts("ERROR IN SETTING THE SCHEDULER");

   530         perror("errno");

   531         return -1;

   532     }

   533 

   534     task = rt_task_init(nam2num("ec_rtai_rtdm_example"),

   535             0 /* priority */, 0 /* stack size */, 0 /* msg size */);

   536 

   537     my_cyclic();

   538 

   539     rt_task_delete(task);

   540 

   541     printf("End of Program\n");

   542     ecrt_release_master(master);

   543 

   544     return 0;

   545 }

   546 

   547 /****************************************************************************/