--- a/NEWS Thu Apr 24 16:01:19 2008 +0000
+++ b/NEWS Fri Apr 25 12:04:23 2008 +0000
@@ -48,6 +48,7 @@
scheduled for reading and writing during realtime operation.
- Exported ecrt_slave_config_sdo(), the generic Sdo configuration
function.
+ - Removed the bus_state and bus_tainted flags from ec_master_state_t.
* Mapping of Pdo entries is now supported.
* Current Pdo assignment/mapping is now read via CoE during bus scan, using
direct Sdo access, independent of the dictionary.
@@ -58,6 +59,12 @@
- Added e1000 driver for kernel 2.6.24, thanks to Matthias Luescher.
- Added alpha support for the Reaktek r8169 chipset, thanks to Scott
Hassan.
+* Removed the "bus validation" routines. Slave scanning is now done any time
+ the bus topology changes, even during realtime operation. Because of this,
+ the bus_tainted flag was deprecated and removed.
+* Slave configuration is not done during ecrt_master_activate() any more, but
+ later during realtime operation. The state of the configuration can be
+ queried via the ecrt_domain_state() and ecrt_slave_config_state() functions.
* Added support for slaves that do not support the LRW datagram type. Separate
domains have to be used for inputs and output.
* Allow gaps in PDO mapping read from CoE.
--- a/TODO Thu Apr 24 16:01:19 2008 +0000
+++ b/TODO Fri Apr 25 12:04:23 2008 +0000
@@ -8,31 +8,39 @@
Version 1.4.0:
-* Remove bus validation; make bus scanning possible at any time.
* Remove self_configured flag to avoid unnecessary process data
interruptions.
* Replace Sysfs interface with cdev and a user space program
to replace lsec; move a few sysfs attributes to proc.
+* Implement realtime interface via cdev.
* Make scanning and configuration run parallel (each).
-* Improve slave config allow flag and completion object.
* Mailbox state machine using toggle bits.
* Mailbox protocol handlers.
-* READMEs for examples.
* Remove get_cycles() calls and references to cpu_khz to increase
portability.
* Remove ecdb.h and let lsec output PDO information 'cut-and-pastable' for
applications.
* SDO write access in sysfs.
* Update documentation.
-* Do not configure in ecrt_master_activate(), but later in the state machine.
* Supply new ec_master_state_t.
* Scanning of Sdo dictionary / writing EEPROM in OPERATION state.
* Adapt remaining examples.
+* READMEs for examples.
* Separate Pdo and Pdo entry classes.
* Attach Pdo names.
* Wait for bus scanning, even when link is not up at ecrt_request_master().
* Implement ecrt_slave_config_state().
* Add something like lsec -n to show numeric vendor IDs.
+* Remove the end state of the master state machine.
+* Rename the sdodict state to sdo_dictionary.
+* Check the position of the acknowledge state.
+* Remove the xmldev files.
+* Remove some debugging (add_sync_manager, clearing station addresses).
+* Rename "Scanning pdo mapping/configuration".
+* Separate CoE debugging.
+* Make ecrt_master_slave_config() return no error when slave is not present
+ or invalid.
+* Remove ec_master_prepare().
Future issues:
--- a/documentation/graphs/fsm_master.dot Thu Apr 24 16:01:19 2008 +0000
+++ b/documentation/graphs/fsm_master.dot Fri Apr 25 12:04:23 2008 +0000
@@ -11,7 +11,6 @@
action_configure [shape=point,label=""]
action_next_slave_state [shape=point,label=""]
action_process_states [shape=point,label=""]
- action_addresses [shape=point,label=""]
start -> broadcast [weight=10]
@@ -33,7 +32,6 @@
action_process_states -> end
action_next_slave_state -> read_states
- action_next_slave_state -> validate_vendor
action_next_slave_state -> action_process_states
//read_states -> error
@@ -43,20 +41,6 @@
//acknowledge -> error
acknowledge -> action_next_slave_state
- //validate_vendor -> error
- validate_vendor -> validate_product
-
- action_addresses -> end
- action_addresses -> rewrite_addresses
-
- //validate_product -> error
- validate_product -> action_addresses
- validate_product -> validate_vendor
-
- //rewrite_addresses -> error
- rewrite_addresses -> end
- rewrite_addresses -> action_addresses
-
//clear_addresses -> error
clear_addresses -> scan_slaves
--- a/include/ecrt.h Thu Apr 24 16:01:19 2008 +0000
+++ b/include/ecrt.h Fri Apr 25 12:04:23 2008 +0000
@@ -85,6 +85,7 @@
* - Added an Sdo access interface, working with Sdo requests. These can be
* scheduled for reading and writing during realtime operation.
* - Exported ecrt_slave_config_sdo(), the generic Sdo configuration function.
+ * - Removed the bus_state and bus_tainted flags from ec_master_state_t.
*
* @{
*/
@@ -148,28 +149,11 @@
/*****************************************************************************/
-/** Bus state.
- *
- * This is used in ec_master_state_t.
- *
- * \deprecated
- * \todo remove
- */
-typedef enum {
- EC_BUS_FAILURE = -1, /**< At least one configured slave is offline. */
- EC_BUS_OK /**< All configured slaves are online. */
-} ec_bus_state_t;
-
-/*****************************************************************************/
-
/** Master state.
*
* This is used for the output parameter of ecrt_master_state().
*/
typedef struct {
- ec_bus_state_t bus_state; /**< \see ec_bus_state_t */
- unsigned int bus_tainted; /**< Non-zero, if the bus topology differs from
- the requested configuration. */
unsigned int slaves_responding; /**< Number of slaves in the bus. */
} ec_master_state_t;
--- a/master/fsm_master.c Thu Apr 24 16:01:19 2008 +0000
+++ b/master/fsm_master.c Fri Apr 25 12:04:23 2008 +0000
@@ -54,9 +54,6 @@
void ec_fsm_master_state_broadcast(ec_fsm_master_t *);
void ec_fsm_master_state_read_states(ec_fsm_master_t *);
void ec_fsm_master_state_acknowledge(ec_fsm_master_t *);
-void ec_fsm_master_state_validate_vendor(ec_fsm_master_t *);
-void ec_fsm_master_state_validate_product(ec_fsm_master_t *);
-void ec_fsm_master_state_rewrite_addresses(ec_fsm_master_t *);
void ec_fsm_master_state_configure_slave(ec_fsm_master_t *);
void ec_fsm_master_state_clear_addresses(ec_fsm_master_t *);
void ec_fsm_master_state_scan_slaves(ec_fsm_master_t *);
@@ -84,8 +81,6 @@
fsm->slaves_responding = 0;
fsm->topology_change_pending = 0;
fsm->slave_states = EC_SLAVE_STATE_UNKNOWN;
- fsm->validate = 0;
- fsm->tainted = 0;
// init sub-state-machines
ec_fsm_slave_config_init(&fsm->fsm_slave_config, fsm->datagram);
@@ -212,16 +207,6 @@
EC_INFO("%u slave%s responding.\n",
fsm->slaves_responding,
fsm->slaves_responding == 1 ? "" : "s");
-
- if (master->mode == EC_MASTER_MODE_OPERATION) {
- if (fsm->slaves_responding == master->slave_count) {
- fsm->validate = 1; // start validation later
- }
- else {
- EC_WARN("Invalid slave count. Bus in tainted state.\n");
- fsm->tainted = 1;
- }
- }
}
// slave states changed?
@@ -236,15 +221,13 @@
down(&master->scan_sem);
if (!master->allow_scan) {
up(&master->scan_sem);
- }
- else {
- master->scan_state = EC_REQUEST_BUSY;
+ } else {
+ master->scan_busy = 1;
up(&master->scan_sem);
// topology change when scan is allowed:
// clear all slaves and scan the bus
fsm->topology_change_pending = 0;
- fsm->tainted = 0;
fsm->idle = 0;
fsm->scan_jiffies = jiffies;
@@ -258,7 +241,7 @@
if (!master->slave_count) {
// no slaves present -> finish state machine.
- master->scan_state = EC_REQUEST_SUCCESS;
+ master->scan_busy = 0;
wake_up_interruptible(&master->scan_queue);
fsm->state = ec_fsm_master_state_end;
return;
@@ -270,7 +253,7 @@
GFP_ATOMIC))) {
EC_ERR("Failed to allocate slave %i!\n", i);
ec_master_destroy_slaves(master);
- master->scan_state = EC_REQUEST_FAILURE;
+ master->scan_busy = 0;
wake_up_interruptible(&master->scan_queue);
fsm->state = ec_fsm_master_state_error;
return;
@@ -279,7 +262,7 @@
if (ec_slave_init(slave, master, i, i + 1)) {
// freeing of "slave" already done
ec_master_destroy_slaves(master);
- master->scan_state = EC_REQUEST_FAILURE;
+ master->scan_busy = 0;
wake_up_interruptible(&master->scan_queue);
fsm->state = ec_fsm_master_state_error;
return;
@@ -504,10 +487,7 @@
return 1;
}
- if (fsm->config_error)
- master->config_state = EC_REQUEST_FAILURE;
- else
- master->config_state = EC_REQUEST_SUCCESS;
+ master->config_busy = 0;
wake_up_interruptible(&master->config_queue);
return 0;
}
@@ -526,12 +506,12 @@
ec_master_t *master = fsm->master;
ec_slave_t *slave;
+ // Start slave configuration, if it is allowed.
down(&master->config_sem);
if (!master->allow_config) {
up(&master->config_sem);
} else {
- master->config_state = EC_REQUEST_BUSY;
- fsm->config_error = 0;
+ master->config_busy = 1;
up(&master->config_sem);
// check for pending slave configurations
@@ -603,25 +583,6 @@
}
// all slave states read
-
- // check, if a bus validation has to be done
- if (fsm->validate) {
- fsm->validate = 0;
- list_for_each_entry(slave, &master->slaves, list) {
- if (slave->online_state == EC_SLAVE_ONLINE) continue;
-
- // At least one slave is offline. validate!
- EC_INFO("Validating bus.\n");
- fsm->idle = 0;
- fsm->slave = list_entry(master->slaves.next, ec_slave_t, list);
- fsm->state = ec_fsm_master_state_validate_vendor;
- ec_fsm_sii_read(&fsm->fsm_sii, slave, 0x0008,
- EC_FSM_SII_USE_INCREMENT_ADDRESS);
- ec_fsm_sii_exec(&fsm->fsm_sii); // execute immediately
- return;
- }
- }
-
ec_fsm_master_action_process_states(fsm);
}
@@ -699,162 +660,6 @@
/*****************************************************************************/
/**
- Master state: VALIDATE_VENDOR.
- Validates the vendor ID of a slave.
-*/
-
-void ec_fsm_master_state_validate_vendor(ec_fsm_master_t *fsm /**< master state machine */)
-{
- ec_slave_t *slave = fsm->slave;
-
- if (ec_fsm_sii_exec(&fsm->fsm_sii)) return;
-
- if (!ec_fsm_sii_success(&fsm->fsm_sii)) {
- fsm->slave->error_flag = 1;
- EC_ERR("Failed to validate vendor ID of slave %i.\n",
- slave->ring_position);
- fsm->state = ec_fsm_master_state_error;
- return;
- }
-
- if (EC_READ_U32(fsm->fsm_sii.value) != slave->sii.vendor_id) {
- EC_ERR("Slave %i has an invalid vendor ID!\n", slave->ring_position);
- fsm->state = ec_fsm_master_state_error;
- return;
- }
-
- // vendor ID is ok. check product code.
- fsm->state = ec_fsm_master_state_validate_product;
- ec_fsm_sii_read(&fsm->fsm_sii, slave, 0x000A,
- EC_FSM_SII_USE_INCREMENT_ADDRESS);
- ec_fsm_sii_exec(&fsm->fsm_sii); // execute immediately
-}
-
-/*****************************************************************************/
-
-/**
- Master action: ADDRESS.
- Looks for slave, that have lost their configuration and writes
- their station address, so that they can be reconfigured later.
-*/
-
-void ec_fsm_master_action_addresses(ec_fsm_master_t *fsm /**< master state machine */)
-{
- ec_datagram_t *datagram = fsm->datagram;
-
- while (fsm->slave->online_state == EC_SLAVE_ONLINE) {
- if (fsm->slave->list.next == &fsm->master->slaves) { // last slave?
- fsm->state = ec_fsm_master_state_end;
- return;
- }
- // check next slave
- fsm->slave = list_entry(fsm->slave->list.next, ec_slave_t, list);
- }
-
- if (fsm->master->debug_level)
- EC_DBG("Reinitializing slave %i.\n", fsm->slave->ring_position);
-
- // write station address
- ec_datagram_apwr(datagram, fsm->slave->ring_position, 0x0010, 2);
- EC_WRITE_U16(datagram->data, fsm->slave->station_address);
- fsm->retries = EC_FSM_RETRIES;
- fsm->state = ec_fsm_master_state_rewrite_addresses;
-}
-
-/*****************************************************************************/
-
-/**
- Master state: VALIDATE_PRODUCT.
- Validates the product ID of a slave.
-*/
-
-void ec_fsm_master_state_validate_product(ec_fsm_master_t *fsm /**< master state machine */)
-{
- ec_slave_t *slave = fsm->slave;
-
- if (ec_fsm_sii_exec(&fsm->fsm_sii)) return;
-
- if (!ec_fsm_sii_success(&fsm->fsm_sii)) {
- fsm->slave->error_flag = 1;
- EC_ERR("Failed to validate product code of slave %i.\n",
- slave->ring_position);
- fsm->state = ec_fsm_master_state_error;
- return;
- }
-
- if (EC_READ_U32(fsm->fsm_sii.value) != slave->sii.product_code) {
- EC_ERR("Slave %i: invalid product code!\n", slave->ring_position);
- EC_ERR("expected 0x%08X, got 0x%08X.\n", slave->sii.product_code,
- EC_READ_U32(fsm->fsm_sii.value));
- fsm->state = ec_fsm_master_state_error;
- return;
- }
-
- // have all states been validated?
- if (slave->list.next == &fsm->master->slaves) {
- fsm->topology_change_pending = 0;
- fsm->tainted = 0;
- fsm->slave = list_entry(fsm->master->slaves.next, ec_slave_t, list);
- // start writing addresses to offline slaves
- ec_fsm_master_action_addresses(fsm);
- return;
- }
-
- // validate next slave
- fsm->slave = list_entry(fsm->slave->list.next, ec_slave_t, list);
- fsm->state = ec_fsm_master_state_validate_vendor;
- ec_fsm_sii_read(&fsm->fsm_sii, slave, 0x0008,
- EC_FSM_SII_USE_INCREMENT_ADDRESS);
- ec_fsm_sii_exec(&fsm->fsm_sii); // execute immediately
-}
-
-/*****************************************************************************/
-
-/**
- Master state: REWRITE ADDRESS.
- Checks, if the new station address has been written to the slave.
-*/
-
-void ec_fsm_master_state_rewrite_addresses(ec_fsm_master_t *fsm
- /**< master state machine */
- )
-{
- ec_slave_t *slave = fsm->slave;
- ec_datagram_t *datagram = fsm->datagram;
-
- if (datagram->state == EC_DATAGRAM_TIMED_OUT && fsm->retries--)
- return;
-
- if (datagram->state != EC_DATAGRAM_RECEIVED) {
- EC_ERR("Failed to receive address datagram for slave %i"
- " (datagram state %i).\n",
- slave->ring_position, datagram->state);
- fsm->state = ec_fsm_master_state_error;
- return;
- }
-
- if (datagram->working_counter != 1) {
- EC_ERR("Failed to write station address of slave %i: ",
- slave->ring_position);
- ec_datagram_print_wc_error(datagram);
- fsm->state = ec_fsm_master_state_error;
- return;
- }
-
- if (fsm->slave->list.next == &fsm->master->slaves) { // last slave?
- fsm->state = ec_fsm_master_state_end;
- return;
- }
-
- // check next slave
- fsm->slave = list_entry(fsm->slave->list.next, ec_slave_t, list);
- // Write new station address to slave
- ec_fsm_master_action_addresses(fsm);
-}
-
-/*****************************************************************************/
-
-/**
* Master state: CLEAR ADDRESSES.
*/
@@ -871,7 +676,7 @@
if (datagram->state != EC_DATAGRAM_RECEIVED) {
EC_ERR("Failed to receive address clearing datagram (state %i).\n",
datagram->state);
- master->scan_state = EC_REQUEST_FAILURE;
+ master->scan_busy = 0;
wake_up_interruptible(&master->scan_queue);
fsm->state = ec_fsm_master_state_error;
return;
@@ -915,13 +720,11 @@
if (!(eoe = kmalloc(sizeof(ec_eoe_t), GFP_KERNEL))) {
EC_ERR("Failed to allocate EoE handler memory for slave %u!\n",
slave->ring_position);
- }
- else if (ec_eoe_init(eoe, slave)) {
+ } else if (ec_eoe_init(eoe, slave)) {
EC_ERR("Failed to init EoE handler for slave %u!\n",
slave->ring_position);
kfree(eoe);
- }
- else {
+ } else {
list_add_tail(&eoe->list, &master->eoe_handlers);
}
}
@@ -938,6 +741,9 @@
EC_INFO("Bus scanning completed in %u ms.\n",
(u32) (jiffies - fsm->scan_jiffies) * 1000 / HZ);
+ master->scan_busy = 0;
+ wake_up_interruptible(&master->scan_queue);
+
// Attach slave configurations
ec_master_attach_slave_configs(master);
@@ -946,9 +752,6 @@
ec_master_eoe_start(master);
#endif
- master->scan_state = EC_REQUEST_SUCCESS;
- wake_up_interruptible(&master->scan_queue);
-
fsm->state = ec_fsm_master_state_end;
}
@@ -966,8 +769,9 @@
if (ec_fsm_slave_config_exec(&fsm->fsm_slave_config)) // execute slave's state machine
return;
- if (!ec_fsm_slave_config_success(&fsm->fsm_slave_config))
- fsm->config_error = 1;
+ if (!ec_fsm_slave_config_success(&fsm->fsm_slave_config)) {
+ // TODO: mark slave_config as failed.
+ }
// configure next slave, if necessary
if (ec_fsm_master_action_configure(fsm))
--- a/master/fsm_master.h Thu Apr 24 16:01:19 2008 +0000
+++ b/master/fsm_master.h Fri Apr 25 12:04:23 2008 +0000
@@ -90,10 +90,6 @@
unsigned int slaves_responding; /**< number of responding slaves */
unsigned int topology_change_pending; /**< bus topology changed */
ec_slave_state_t slave_states; /**< states of responding slaves */
- unsigned int validate; /**< non-zero, if validation to do */
- unsigned int tainted; /**< non-zero, if the current bus topology does
- not meet the initial conditions */
- unsigned int config_error; /**< error during slave configuration */
ec_slave_t *slave; /**< current slave */
ec_sii_write_request_t *sii_request; /**< SII write request */
off_t sii_index; /**< index to SII write request data */
--- a/master/master.c Thu Apr 24 16:01:19 2008 +0000
+++ b/master/master.c Fri Apr 25 12:04:23 2008 +0000
@@ -126,12 +126,12 @@
INIT_LIST_HEAD(&master->configs);
- master->scan_state = EC_REQUEST_SUCCESS;
+ master->scan_busy = 0;
master->allow_scan = 1;
init_MUTEX(&master->scan_sem);
init_waitqueue_head(&master->scan_queue);
- master->config_state = EC_REQUEST_SUCCESS;
+ master->config_busy = 0;
master->allow_config = 1;
init_MUTEX(&master->config_sem);
init_waitqueue_head(&master->config_queue);
@@ -146,7 +146,6 @@
master->stats.corrupted = 0;
master->stats.unmatched = 0;
master->stats.output_jiffies = 0;
- master->pdo_slaves_offline = 0; // assume all Pdo slaves online
master->frames_timed_out = 0;
for (i = 0; i < HZ; i++) {
@@ -442,36 +441,38 @@
down(&master->config_sem);
master->allow_config = 0; // temporarily disable slave configuration
- up(&master->config_sem);
-
- // wait for slave configuration to complete
- if (wait_event_interruptible(master->config_queue,
- master->config_state != EC_REQUEST_BUSY)) {
- EC_INFO("Finishing slave configuration interrupted by signal.\n");
- goto out_allow;
- }
-
- if (master->debug_level)
- EC_DBG("Waiting for pending slave configuration returned.\n");
-
- if (master->debug_level)
- EC_DBG("Disable scanning, current scan state: %u\n",
- master->scan_state);
+ if (master->config_busy) {
+ up(&master->config_sem);
+
+ // wait for slave configuration to complete
+ if (wait_event_interruptible(master->config_queue,
+ !master->config_busy)) {
+ EC_INFO("Finishing slave configuration interrupted by signal.\n");
+ goto out_allow;
+ }
+
+ if (master->debug_level)
+ EC_DBG("Waiting for pending slave configuration returned.\n");
+ } else {
+ up(&master->config_sem);
+ }
+
down(&master->scan_sem);
master->allow_scan = 0; // 'lock' the slave list
- up(&master->scan_sem);
-
- if (master->scan_state == EC_REQUEST_BUSY) {
+ if (!master->scan_busy) {
+ up(&master->scan_sem);
+ } else {
+ up(&master->scan_sem);
+
// wait for slave scan to complete
- if (wait_event_interruptible(master->scan_queue,
- master->scan_state != EC_REQUEST_BUSY)) {
+ if (wait_event_interruptible(master->scan_queue, !master->scan_busy)) {
EC_INFO("Waiting for slave scan interrupted by signal.\n");
goto out_allow;
}
- }
-
- if (master->debug_level)
- EC_DBG("Waiting for pending slave scan returned.\n");
+
+ if (master->debug_level)
+ EC_DBG("Waiting for pending slave scan returned.\n");
+ }
// set states for all slaves
list_for_each_entry(slave, &master->slaves, list) {
@@ -1005,11 +1006,6 @@
off += sprintf(buffer + off, "\nSlaves: %i\n",
master->slave_count);
- off += sprintf(buffer + off, "Status: %s\n",
- master->fsm.tainted ? "TAINTED" : "sane");
- off += sprintf(buffer + off, "Pdo slaves: %s\n",
- master->pdo_slaves_offline ? "INCOMPLETE" : "online");
-
off += sprintf(buffer + off, "\nDevices:\n");
down(&master->device_sem);
@@ -1349,26 +1345,9 @@
domain_offset += domain->data_size;
}
- // request slave configuration
- down(&master->config_sem);
master->allow_config = 1; // request the current configuration
- up(&master->config_sem);
-
- if (master->main_device.link_state) {
- // wait for configuration to complete
- master->config_state = EC_REQUEST_BUSY;
- if (wait_event_interruptible(master->config_queue,
- master->config_state != EC_REQUEST_BUSY)) {
- EC_INFO("Waiting for configuration interrupted by signal.\n");
- return -1;
- }
-
- if (master->config_state != EC_REQUEST_SUCCESS) {
- EC_ERR("Failed to configure slaves.\n");
- return -1;
- }
- }
-
+ master->allow_scan = 1; // allow re-scanning on topology change
+
// restart EoE process and master thread with new locking
#ifdef EC_EOE
ec_master_eoe_stop(master);
@@ -1390,6 +1369,7 @@
EC_ERR("Failed to start master thread!\n");
return -1;
}
+
#ifdef EC_EOE
ec_master_eoe_start(master);
#endif
@@ -1532,10 +1512,6 @@
void ecrt_master_state(const ec_master_t *master, ec_master_state_t *state)
{
- state->bus_state =
- (master->pdo_slaves_offline || master->frames_timed_out)
- ? EC_BUS_FAILURE : EC_BUS_OK;
- state->bus_tainted = master->fsm.tainted;
state->slaves_responding = master->fsm.slaves_responding;
}
--- a/master/master.h Thu Apr 24 16:01:19 2008 +0000
+++ b/master/master.h Fri Apr 25 12:04:23 2008 +0000
@@ -104,14 +104,14 @@
struct list_head configs; /**< Bus configuration list. */
unsigned int configs_attached; /**< Slave configurations were attached. */
- ec_request_state_t scan_state; /**< current scanning state */
+ unsigned int scan_busy; /**< Current scan state. */
unsigned int allow_scan; /**< non-zero, if slave scanning is allowed */
struct semaphore scan_sem; /**< semaphore protecting the scan_state
variable and the allow_scan flag */
wait_queue_head_t scan_queue; /**< queue for processes that wait for
slave scanning */
- ec_request_state_t config_state; /**< state of slave configuration */
+ unsigned int config_busy; /**< State of slave configuration. */
unsigned int allow_config; /**< non-zero, if slave scanning is allowed */
struct semaphore config_sem; /**< semaphore protecting the config_state
variable and the allow_config flag */
@@ -125,9 +125,6 @@
int debug_level; /**< master debug level */
ec_stats_t stats; /**< cyclic statistics */
- unsigned int pdo_slaves_offline; /**< number of slaves, for which Pdos
- were registered and that are offline
- (used for bus status) */
unsigned int frames_timed_out; /**< there were frame timeouts in the last
call to ecrt_master_receive() */