Description
Original instructions
Function description
This function block enables PID control of servo motors with or without positional feedback. The function block can be switched to be the controller (PIDFF, PI_B) so that the digital outputs become the two logical outputs RAISE and LOWER.
If the function block uses positional feedback, then positioning controlling of the actuator will be performed. If positional feedback is not being used, the controller and the SERVO function block operate a continuous static control together.
EN and ENO can be configured as additional parameters.
Representation in FBD
Representation:
Representation in LD
Representation:
Representation in IL
Representation:
CAL SERVO_Instance (SEN:=New_INPD_Or_IN_ValueFlag, 
    IN:=ControllerOutputOUT, INPD:=VariationOf_IN, 
    MA_I:=OperatingMode, RCPY:=PositionalCopy, 
    RST:=BlockReinitialization, 
    R_STOP:=ReachedEndstopOfRAISE, 
    L_STOP:=ReachedEndstopOfLOWER, PARA:=Parameters, 
    RAISE=>TravelDirectionOfRAISE, 
    LOWER=>TravelDirectionOfLOWER, STATUS=>StatusWord)
Representation in ST
Representation:
SERVO_Instance (SEN:=New_INPD_Or_IN_ValueFlag, 
    IN:=ControllerOutputOUT, INPD:=VariationOf_IN, 
    MA_I:=OperatingMode, RCPY:=PositionalCopy, 
    RST:=BlockReinitialization, 
    R_STOP:=ReachedEndstopOfRAISE, 
    L_STOP:=ReachedEndstopOfLOWER, PARA:=Parameters, 
    RAISE=>TravelDirectionOfRAISE, 
    LOWER=>TravelDirectionOfLOWER, STATUS=>StatusWord) ;
Parameter description SERVO
Input parameter description:
Parameter
Data type
Meaning
SEN
"1" : Including a new value at the INPD or IN inputs
"0" : no inclusion of the new values of INPD or IN
IN
Control output OUT (0 to 100%)
INPD
REAL
Output alteration OUTD of the controller (-100% to 100%)
MA_I
BOOL
Control operating mode (Output MA_O)
"1" : Automatic mode
"0" : Manual or tracking mode
RCPY
REAL
Positional feedback (0 to 100%)
RST
BOOL
"1" : Reinitialization of the function block (resetting outputs and the internal function block status)
R_STOP
BOOL
End position RAISE reached
L_STOP
BOOL
End position LOWER reached
PARA
Parameter
Output parameter description:
Parameter
Data type
Meaning
RAISE
BOOL
Logical output in the direction RAISE
LOWER
BOOL
Logical output in the direction LOWER
STATUS
Status word
Parameter description Para_SERVO
Data structure description
Element
Data type
Meaning
en_rcpy
"1" : Function with positional feedback (including RCPY)
rcpy_rev
BOOL
"1" : Inversion of RCPY
"0" : no inversion of RCPY
t_motor
Actuator opening time
t_mini
TIME
Minimum impulse length