Trace

Files
file	CO_trace.h
	CANopen trace object for recording variables over time.

Data Structures
struct	CO_trace_dataType_t
	structure for reading variables and printing points for specific data type. More...
struct	CO_trace_t
	Trace object. More...

Macros
#define	OD_INDEX_TRACE_CONFIG   0x2301
	Start index of traceConfig and Trace objects in Object Dictionary.

Functions
void	CO_trace_init (CO_trace_t *trace, CO_SDO_t *SDO, uint8_t enabled, uint32_t *timeBuffer, int32_t *valueBuffer, uint32_t bufferSize, uint32_t *map, uint8_t *format, uint8_t *trigger, int32_t *threshold, int32_t *value, int32_t *minValue, int32_t *maxValue, uint32_t *triggerTime, uint16_t idx_OD_traceConfig, uint16_t idx_OD_trace)
	Initialize trace object. More...
void	CO_trace_process (CO_trace_t *trace, uint32_t timestamp)
	Process trace object. More...

Detailed Description

CANopen trace object for recording variables over time.

In embedded systems there is often a need to monitor some variables over time. Results are then displayed on graph, similar as in oscilloscope.

CANopen trace is a configurable object, accessible via CANopen Object Dictionary, which records chosen variable over time. It generates a curve, which can be read via SDO and can then be displayed in a graph.

CO_trace_process() runs in 1 ms intervals and monitors one variable. If it changes, it makes a record with timestamp into circular buffer. When trace is accessed by CANopen SDO object, it reads latest points from the the circular buffer, prints a SVG curve into string and sends it as a SDO response. If a SDO request was received from the same device, then no traffic occupies CAN network.

Function Documentation

CO_trace_init()

void CO_trace_init	(	CO_trace_t *	trace,
		CO_SDO_t *	SDO,
		uint8_t	enabled,
		uint32_t *	timeBuffer,
		int32_t *	valueBuffer,
		uint32_t	bufferSize,
		uint32_t *	map,
		uint8_t *	format,
		uint8_t *	trigger,
		int32_t *	threshold,
		int32_t *	value,
		int32_t *	minValue,
		int32_t *	maxValue,
		uint32_t *	triggerTime,
		uint16_t	idx_OD_traceConfig,
		uint16_t	idx_OD_trace
	)

Initialize trace object.

Function must be called in the communication reset section.

Parameters

trace	This object will be initialized.
SDO	SDO server object.
enabled	Is trace enabled.
timeBuffer	Memory block for storing time records.
valueBuffer	Memory block for storing value records.
bufferSize	Size of the above buffers.
map	Map to variable in Object Dictionary, which will be monitored. Same structure as in PDO.
format	Format of the plot. If first bit is 1, above variable is unsigned. For more info see Object Dictionary.
trigger	If different than zero, trigger time is recorded, when variable goes through threshold.
threshold	Used with trigger.
value	Pointer to variable, which will show last value of the variable.
minValue	Pointer to variable, which will show minimum value of the variable.
maxValue	Pointer to variable, which will show maximum value of the variable.
triggerTime	Pointer to variable, which will show last trigger time of the variable.
idx_OD_traceConfig	Index in Object Dictionary.
idx_OD_trace	Index in Object Dictionary.

Returns

0 on success, -1 on error.

CO_trace_process()

void CO_trace_process	(	CO_trace_t *	trace,
		uint32_t	timestamp
	)

Process trace object.

Function must be called cyclically in 1ms intervals.

Parameters

trace	This object.
timestamp	Timestamp (usually in millisecond resolution).

Returns

0 on success, -1 on error.