Speed Limiter

Description

This function is used, when changing setpoint, to reach the new value while respecting a speed limit. Rising and descending speed limits can be different.

When the requested value on input is greater than the current value of the output SP, the function increases the value of this output at the speed R_RATE, until the value SP is equal to that requested.

If the value R_RATE is nil, there is no slope and SP is a direct copy of the input value.

When the input value changes as the slope is being generated the function attempts to reach this new target.

Function diagram:

Parameters

Input Parameter:

Parameter	Symbol	Type	Thresholds	Default Value	R/W
Setpoint Value	SP	REAL	-3.4E38 / 3.4E38	/	R

Internal parameters:

Parameter	Symbol	Type	Thresholds	Default Value	R/W
Rising speed limit	R_RATE	REAL	0.0 / 3.4E38	0.0	R/W
Descending speed limit	D_RATE	REAL	0.0 / 3.4E38	0.0	R/W

Output Parameter:

Parameter	Symbol	Type	Thresholds	Default Value	R/W
Limited Setpoint Value	SPEED_LIM_OUT	REAL	-3.4E38 / 3.4E38	/	R/W

NOTE: R_RATE and D_RATE at 0.0 mean there is no limit.

This function can be applied to the Remote setpoint and the local setpoint or only to the local setpoint, according to the chosen configuration.

Execution Monitoring

Monitoring the parameters of this function is integrated into the error management of the setpoint branch.