Auto-Tuning Parameters

Internal Parameters

Internal parameters of the auto-tuning function are as follows:

Parameter	Symbol	Type	Thresholds	Default Value	R/W
Size of command division (%)	AT_STEP	REAL	-100.0 / 100.0	10.0	R/W
Duration of the scale (s)	AT_TMAX	REAL	4,0 / 3.4E38	100.0	R/W
Criteria for auto-tuning performance	AT_PERF	REAL	0.0 / 1.0	0.5	R/W
Proportional gain	KP	REAL	0.0 / 3.4E38	1.0	R/W
Integral time (s) (*)	TI	REAL	0.0 / 3.4E38	0.0	R/W
Derivation time (s) (**)	TD	REAL	0.0 / 3.4E38	0.0	R/W
Model gain (***)	KS	REAL	0.0 / 3.4E38	1.0	R/W
Model time constant (s) (***)	T1	REAL	0.0 / 3.4E38	0.0	R/W
Model delay (s) (***)	T_DELAY	REAL	0.0 / 3.4E38	0.0	R/W

(*) According to the loop controller used (PID or model loop controller).

(**) See PID loop controller.

(***) See model loop controller.

Output Parameters

For the output parameters, the range of variation (limits) and default value have no object. Therefore, these columns have not been given in the table in order to make it more readable.

Output parameters of the auto-tuning function are as follows:

Parameter	Symbol	Type	R/W
Value before proportional coefficient auto-tuning or model gain	KP_PREV	REAL	R
Value before integral coefficient auto-tuning or time constant model	TI_PREV	REAL	R
Value before derived coefficient auto-tuning or model delay	TD_PREV	REAL	R
Auto-tuning in progress	STS_AT_RUNNING	EBOOL	R
Auto-tuning failed	AT_FAILED	EBOOL	R
Auto-tuning diagnostics interrupted	AT_ABORTED	EBOOL	R
Auto-tuning diagnostics parameter error	AT_ERR_PARAM	EBOOL	R
Auto-tuning diagnostics system error or power failure	AT_ERR_PWF_OR_EFB_FAIL	EBOOL	R
Auto-tuning diagnostics process value or actuator saturation	AT_ERR_SATUR	EBOOL	R
Auto-tuning diagnostics insufficient process value deviation	AT_DV_TOO_SMALL	EBOOL	R
Auto-tuning Diagnostics sampling period too large	AT_TSAMP_HIGH	EBOOL	R
Auto-tuning diagnostics inconsistent response	AT_INCONSIST_RESP	EBOOL	R
Auto-tuning diagnostics process value initially unstable	AT_NOT_STAB_INIT	EBOOL	R
Auto-tuning diagnostics scale period too small	AT_TMAX_TOO_SMALL	EBOOL	R
Auto-tuning diagnostics process value noise too high	AT_NOISE_TOO_HIGH	EBOOL	R
Auto-tuning diagnostics division period too large	AT_TMAX_TOO_HIGH	EBOOL	R
Auto-tuning diagnostics overflow > 10%	AT_OVERSHOOT	EBOOL	R
Auto-tuning diagnostics step minimum too high	AT_UNDERSHOOT	EBOOL	R
Auto-tuning diagnostics procedure not symmetrical enough	AT_UNSYMETRICAL_PT	EBOOL	R
Auto-tuning diagnostics integrating process	AT_INTEGRATING_PT	EBOOL	R