Lenze DDS Global Drive PLC Developer Studio - Manual (Page 17)

Function block library LenzeElectricalShaft.lib
Special functions
2.1.1 Digital frequency ramp generator (L_DFRFG)
2−7
L
LenzeElectricalShaft.lib EN 1.2
Setting the initial values of L_DFRFG1 in the Instance−Parameter Manager
·
Alter the initial value of byFunction from 0 to 1.
The start of synchronization is then initiated throught the Touchprobe input (X5/E5) of the SB
DF_IN_DigitalFrequency ( L_DFRFG.bSetTPReceived_b).
DFIN_dnIncLastScan_p assigns the phase difference between the appearance of the
Touchprobe signal and the start of the task in which L_DFRFG1 is called, for the calculation of
the path, to L_DFRFG1 .
·
Alter the initial value of dwTir from 1.000 to 10.000, so that the ramp−up/ramp−down time of
the ramp generator is 10 seconds.
·
The initial value of bySpeedDirection includes the Lenze standard setting (DF=1), since both
cw (right) and ccw (left) rotation should be possible.
·
The initial value of nMaxSpeed includes the Lenze standard setting (DF=3000), so the
maximum speed of the profile generator will be 3000 rpm. (17476
º 16000 rpm)
Speed setpoint
·
L_DFRFG1 assigns the speed setpoint, through L_DFSET1 ( nSetSpeedOut_a ) to the SB
MCTRL_MotorControl ( MCTRL_nNSet_a).
·
In L_DFSET1 a conversion is made from a velocity valuer (L_DFRFG1.nOut_v) to an analog
value ( L_DFSET1.nSetSpeedOut_a):
<Variable>_v: 16384
º 15000 rpm
<Variable>_a: 16384
º n
max
(C0011)
·
During synchronization, the speed setpoint is generated by the synchronization profile (profile
generator) and output to L_DFRFG1.nOut_v (16384
º 15000 rpm).
·
After synchronization, the speed setpoint is switched over from L_DFRFG1.nIn_v to
L_DFRFG1.nOut_v , the setpoint now follows the value of the digital frequency input.
Setpoint for the phase−angle controller
A set/actual phase−angle comparison provides an phase−angle difference that is assigned to the
phase−angle controller in the SB MCTRL_ MotorControl. If there is a difference between the set
value and the actual value, the phase−angle controller corrects this deviation.
·
The phase−angle controller in the SB MCTRL_MotorControl must be activated. (
MCTRL_bPosOn_b = TRUE)
·
The set/actual value comparison is performed in L_DFSET1 between L_DFSET1.nSet_v
(setpoint) and L_DFSET1.nNAct_v (actual value).
·
The phase−angle difference is output via L_DFSET1.dnPosDiffOut_p, and then assigned to the
phase−angle controller in the SB MCTRL_ MotorControl through the system variable
MCTRL_dnPosSet_p.