SoemMaster Class Reference

#include <soem_master.h>

Inheritance diagram for SoemMaster:

Collaboration diagram for SoemMaster:

Public Member Functions
	SoemMaster (Notifier &notifier, const std::string &ifname)
	Initializes the SOEM EtherCAT master and brings all discovered slaves to OPERATIONAL state.
	~SoemMaster () override
size_t	start () override
	Start the EtherCAT master.
void	stop () override
	Stop the EtherCAT master.
size_t	restart () override
	Returns the number of EtherCAT slaves during a restart.
int32_t	execute (uint64_t pending_signals) override
	Main EtherCAT master loop function to be executed at one millisecond interval.
bool	is_running () override
	Check if the EtherCAT master is currently running.
int	get_slaves_responding () override
	Return the number of slaves actually responding on the bus.
std::list< VirtualDevice * >	get_slaves () override
	Get all of the available slaves.
bool	disable_all_slaves () override
	Switch all slaves to PREOP.
int	roundtrip ()
void	checkstate ()
Public Member Functions inherited from EthercatMaster
virtual	~EthercatMaster ()=default

Static Public Member Functions
static void	wait_for_slaves (Notifier &notifier, const std::string &ifname)

Static Public Attributes
static std::map< uint16_t, std::unique_ptr< EthercatSlave > >	slaveMap {}
	Static map of EtherCAT slave instances.

Constructor & Destructor Documentation

SoemMaster()

SoemMaster::SoemMaster ( Notifier & notifier, const std::string & ifname )

explicit

Initializes the SOEM EtherCAT master and brings all discovered slaves to OPERATIONAL state.

Performs the full EtherCAT startup sequence:

1. Manual state change — Sets ecx_context.manualstatechange = TRUE so that ecx_config_map_group does not automatically advance slaves to SAFE-OP. Without this, SOMANET devices without firmware that reach SAFE-OP become stuck and require a power cycle to recover.
2. Slave discovery — Calls g_soem_update_slavecount() and creates a SoemSlave for every responding slave. Only supported devices are added to slaveMap; others are silently skipped.
3. Parallel PRE-OP transition — All slaves in slaveMap are transitioned to PRE-OPERATIONAL concurrently (10 retries, 500 ms timeout per attempt).
4. Sequential slave initialization — Each slave in slaveMap is initialized one at a time to avoid SDO mailbox contention. Third-party devices (neither Synapticon nor Sensodrive vendor ID) are skipped entirely. For each Synapticon/Sensodrive slave:
   • If still in INIT after the PRE-OP attempt (likely missing firmware), it is first re-set to INIT (Integro workaround) and then transitioned to BOOT so firmware can be uploaded via FoE.
   • SoemSlave::initialize() is called for all states; it reads state internally and performs full init for PRE-OP or hardware ID only for BOOT.
   • OD entry values are refreshed only for slaves that reached PRE-OP.
5. Early-exit guard — Rechecks the slave count. If all slaves have disappeared (e.g. powered off during initialization), the constructor returns early to avoid hanging inside ecx_config_map_group.
6. PDO mapping — ecx_config_map_group configures and maps all Process Data Objects.
7. Parallel SAFE-OP transition — Each slave's current state is read; only those confirmed to be in PRE-OP are transitioned to SAFE-OP.
8. PDO roundtrip — A single roundtrip() call primes slave outputs before the final state transition.
9. Parallel OP transition — Each slave's current state is read; only those confirmed to be in SAFE-OP are transitioned to OPERATIONAL.

Parameters

notifier	Reference to the notification bus used to publish EtherCAT events to the rest of the system.
ifname	Network interface name for the EtherCAT master port (e.g. "eth0").

~SoemMaster()

SoemMaster::~SoemMaster ( )

override

Member Function Documentation

checkstate()

void SoemMaster::checkstate

(

)

disable_all_slaves()

bool SoemMaster::disable_all_slaves ( )

overridevirtual

Switch all slaves to PREOP.

Attention

Must be implemented as non-blocking!

Returns

true on success, false otherwise

Implements EthercatMaster.

execute()

int32_t SoemMaster::execute ( uint64_t pending_signals )

overridevirtual

Main EtherCAT master loop function to be executed at one millisecond interval.

Returns

error if any

Implements EthercatMaster.

get_slaves()

std::list< VirtualDevice * > SoemMaster::get_slaves ( )

overridevirtual

Get all of the available slaves.

Returns

map of available slaves

Implements EthercatMaster.

get_slaves_responding()

int SoemMaster::get_slaves_responding ( )

overridevirtual

Return the number of slaves actually responding on the bus.

Returns

number of responding slaves

Implements EthercatMaster.

is_running()

bool SoemMaster::is_running ( )

overridevirtual

Check if the EtherCAT master is currently running.

Returns

true if currently running, false otherwise

Implements EthercatMaster.

restart()

size_t SoemMaster::restart ( )

overridevirtual

Returns the number of EtherCAT slaves during a restart.

A restart is triggered when transitioning from PRE-OP to OP, typically due to updated PDO mappings on a device.

Returns

Current EtherCAT slave count.

Implements EthercatMaster.

roundtrip()

int SoemMaster::roundtrip

(

)

start()

size_t SoemMaster::start ( )

overridevirtual

Start the EtherCAT master.

Returns

the number of initially responding slaves

Implements EthercatMaster.

stop()

void SoemMaster::stop ( )

overridevirtual

Stop the EtherCAT master.

Implements EthercatMaster.

wait_for_slaves()

void SoemMaster::wait_for_slaves ( Notifier & notifier, const std::string & ifname )

static

Member Data Documentation

slaveMap

std::map< uint16_t, std::unique_ptr< EthercatSlave > > SoemMaster::slaveMap {}

static

Static map of EtherCAT slave instances.

The slaveMap is declared static because other components of the system, such as ParameterValueRefresher, may hold raw pointers to instances of EthercatSlave (retrieved via SoemMaster::get_slaves()).

If slaveMap were a non-static member of SoemMaster, it would be destroyed when the SoemMaster instance goes out of scope. Since slaveMap holds std::unique_ptrs, this would also delete the associated slave objects and their Object Dictionary (OD) entries. Consequently, any component still holding raw pointers to those objects would be left with dangling references, leading to undefined behavior.

Declaring slaveMap as static ensures that these instances persist beyond the lifetime of a single SoemMaster instance, preventing invalid memory access.

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The documentation for this class was generated from the following files:

• apps/motion_master/soem_master.h
• apps/motion_master/soem_master.cc