Node Guarding CANopen Node Guarding, an older alternative to the Heartbeat protocol.

Collaboration diagram for Node Guarding CANopen Node Guarding, an older alternative to the Heartbeat protocol.:

Files
file	CO_Node_Guarding.h
	CANopen Node Guarding slave and master objects.

Data Structures
struct	CO_nodeGuardingSlave_t
	Node Guarding slave object. More...
struct	CO_nodeGuardingMasterNode_t
	Node Guarding master - monitored node. More...
struct	CO_nodeGuardingMaster_t
	Node Guarding master object. More...

Functions
CO_ReturnError_t	CO_nodeGuardingSlave_init (CO_nodeGuardingSlave_t *ngs, OD_entry_t *OD_100C_GuardTime, OD_entry_t *OD_100D_LifeTimeFactor, CO_EM_t *em, uint16_t CANidNodeGuarding, CO_CANmodule_t *CANdevRx, uint16_t CANdevRxIdx, CO_CANmodule_t *CANdevTx, uint16_t CANdevTxIdx, uint32_t *errInfo)
	Initialize Node Guarding slave object.
void	CO_nodeGuardingSlave_process (CO_nodeGuardingSlave_t *ngs, CO_NMT_internalState_t NMTstate, bool_t slaveDisable, uint32_t timeDifference_us, uint32_t *timerNext_us)
	Process Node Guarding slave.
static bool_t	CO_nodeGuardingSlave_isTimeout (CO_nodeGuardingSlave_t *ngs)
	Inquire, if Node guarding slave detected life time timeout.
CO_ReturnError_t	CO_nodeGuardingMaster_init (CO_nodeGuardingMaster_t *ngm, CO_EM_t *em, CO_CANmodule_t *CANdevRx, uint16_t CANdevRxIdx, CO_CANmodule_t *CANdevTx, uint16_t CANdevTxIdx)
	Initialize Node Guarding master object.
CO_ReturnError_t	CO_nodeGuardingMaster_initNode (CO_nodeGuardingMaster_t *ngm, uint8_t index, uint8_t nodeId, uint16_t guardTime_ms)
	Initialize node inside Node Guarding master object.
void	CO_nodeGuardingMaster_process (CO_nodeGuardingMaster_t *ngm, uint32_t timeDifference_us, uint32_t *timerNext_us)
	Process Node Guarding master.

Detailed Description

Node guarding master pools each node guarding slave at time intervals, called guard time. Master sends a CAN RTR message, and slave responds. Slave also monitors presence of RTR message from master and indicates error, if it wasn't received within life time. ('Life time' is 'Guard time' multiplied by 'Life time factor').

Adding Node guarding to the project:

• Make sure, driver supports it. RTR bit should be part of CAN identifier.
• Enable it with 'CO_CONFIG_NODE_GUARDING', see CO_config.h
• For slave add 0x100C and 0x100D objects to the Object dictionary.
• For master use CO_nodeGuardingMaster_initNode() to add monitored nodes.

Warning

Usage of Node guarding is not recommended, as it is outdated and uses RTR CAN functionality, which is also not recommended. Use Heartbeat and Heartbeat consumer, if possible.

Node Guarding slave response message contents:

Byte, bits	Description
0, bits 0..6	CO_NMT_internalState_t
0, bit 7	toggle bit

See Default CANopen identifiers for CAN identifiers.

Function Documentation

CO_nodeGuardingSlave_init()

CO_ReturnError_t CO_nodeGuardingSlave_init	(	CO_nodeGuardingSlave_t *	ngs,
		OD_entry_t *	OD_100C_GuardTime,
		OD_entry_t *	OD_100D_LifeTimeFactor,
		CO_EM_t *	em,
		uint16_t	CANidNodeGuarding,
		CO_CANmodule_t *	CANdevRx,
		uint16_t	CANdevRxIdx,
		CO_CANmodule_t *	CANdevTx,
		uint16_t	CANdevTxIdx,
		uint32_t *	errInfo )

Initialize Node Guarding slave object.

Function must be called in the communication reset section.

Parameters

	ngs	This object will be initialized.
	OD_100C_GuardTime	OD entry for 0x100C -"Guard time", entry is required.
	OD_100D_LifeTimeFactor	OD entry for 0x100D -"Life time factor", entry is required.
	em	Emergency object.
	CANidNodeGuarding	CAN identifier for Node Guarding rtr and response message (usually CO_CAN_ID_HEARTBEAT + nodeId).
	CANdevRx	CAN device for Node Guarding rtr reception.
	CANdevRxIdx	Index of the receive buffer in the above CAN device.
	CANdevTx	CAN device for Node Guarding response transmission.
	CANdevTxIdx	Index of the transmit buffer in the above CAN device.
[out]	errInfo	Additional information in case of error, may be NULL.

Returns

CO_ReturnError_t CO_ERROR_NO on success.

CO_nodeGuardingSlave_process()

void CO_nodeGuardingSlave_process	(	CO_nodeGuardingSlave_t *	ngs,
		CO_NMT_internalState_t	NMTstate,
		bool_t	slaveDisable,
		uint32_t	timeDifference_us,
		uint32_t *	timerNext_us )

Process Node Guarding slave.

Function must be called cyclically.

Parameters

	ngs	This object.
	NMTstate	NMT operating state.
	slaveDisable	If true, then Node guarding slave is disabled.
	timeDifference_us	Time difference from previous function call in microseconds.
[out]	timerNext_us	info to OS - see CO_process().

CO_nodeGuardingSlave_isTimeout()

static bool_t CO_nodeGuardingSlave_isTimeout ( CO_nodeGuardingSlave_t * ngs )

inlinestatic

Inquire, if Node guarding slave detected life time timeout.

Error is reset after pool request from master.

Parameters

ngs	This object.

Returns

true, if life time timeout was detected.

CO_nodeGuardingMaster_init()

CO_ReturnError_t CO_nodeGuardingMaster_init	(	CO_nodeGuardingMaster_t *	ngm,
		CO_EM_t *	em,
		CO_CANmodule_t *	CANdevRx,
		uint16_t	CANdevRxIdx,
		CO_CANmodule_t *	CANdevTx,
		uint16_t	CANdevTxIdx )

Initialize Node Guarding master object.

Function must be called in the communication reset section.

Parameters

ngm	This object will be initialized.
em	Emergency object.
CANdevRx	CAN device for Node Guarding reception.
CANdevRxIdx	Index of the receive buffer in the above CAN device.
CANdevTx	CAN device for Node Guarding rtr transmission.
CANdevTxIdx	Index of the transmit buffer in the above CAN device.

Returns

CO_ReturnError_t CO_ERROR_NO on success.

CO_nodeGuardingMaster_initNode()

CO_ReturnError_t CO_nodeGuardingMaster_initNode	(	CO_nodeGuardingMaster_t *	ngm,
		uint8_t	index,
		uint8_t	nodeId,
		uint16_t	guardTime_ms )

Initialize node inside Node Guarding master object.

Function may be called any time after CO_nodeGuardingMaster_init(). It configures monitoring of the remote node.

Parameters

ngm	Node Guarding master object.
index	Index of the slot, which will be configured. 0 <= index < CO_CONFIG_NODE_GUARDING_MASTER_COUNT.
nodeId	Node Id of the monitored node.
guardTime_ms	Guard time of the monitored node.

Returns

CO_ReturnError_t CO_ERROR_NO on success.

CO_nodeGuardingMaster_process()

void CO_nodeGuardingMaster_process	(	CO_nodeGuardingMaster_t *	ngm,
		uint32_t	timeDifference_us,
		uint32_t *	timerNext_us )

Process Node Guarding master.

Function must be called cyclically.

Parameters

	ngm	This object.
	timeDifference_us	Time difference from previous function call in microseconds.
[out]	timerNext_us	info to OS - see CO_process().