9.4.3.6
Input parameters PULSEGEN
The values of the input parameters are not limited in the block. There is no parameter check.
Table 9- 17
Input parameters PULSEGEN
Parameters
Data
type
INV
REAL
PER_TM
TIME
P_B_TM
TIME
RATIOFAC
REAL
STEP3_ON
BOOL
ST2BI_ON
BOOL
MAN_ON
BOOL
POS_P_ON
BOOL
NEG_P_ON
BOOL
SYN_ON
BOOL
COM_RST
BOOL
CYCLE
TIME
PID control
Function Manual, 03/2017, A5E35300227-AC
Default
Description
0.0
At the input parameter "Input variable" an analog manipulated variable is con-
nected.
Values from -100 to 100 % are permitted.
T#1s
At the parameter "Period duration" the constant period duration of the pulse
width modulation is entered. This corresponds to the
s ampling time of the con-
troller. The ratio
b etween the sampling time of the pulse
s haper and the sam-
pling time of the
c ontroller determines the accuracy of the
p ulse width
modulation.
PER_TM >=20*CYCLE
T#50 ms
You can assign a minimum pulse/break time at the parameter "Minimum
pulse/break time".
P_B_TM >= CYCLE
1.0
Using the "Ratio factor" input parameter the ratio of the duration of positive to
negative pulses can be changed. In a thermal
p rocess, this would, for example,
allow
d ifferent time constants for heating and
c ooling to be compensated (for
example, in
a process with electrical heating and water
c ooling).
Values from 0.1 to 10.0 are permitted.
TRUE
At the input parameter "Enable three-step control" the appropriate mode is
activated. In three-step control
b oth output signals are active.
FALSE
At the input parameter "Enable two-step control for bipolar manipulated value
range" you can select from the modes "Two-step control for bipolar manipulated
value range" and "Two-step control for unipolar manipulated value range".
STEP3_ON = FALSE is required.
FALSE
Setting the input parameter "Enable manual mode" allows the output signals to
be set manually.
FALSE
For manual mode three-step control, the output signal QPOS_P can be operat-
ed on the input parameter "Positive pulse on". In
m anual mode with two-step
control, QNEG_P is always set inversely to
QPOS_P.
FALSE
For manual mode three-step control, the output signal QNEG_P can be operat-
ed on the input parameter "Negative pulse on". In
m anual mode with two-step
control, QNEG_P is always set inversely to
QPOS_P.
TRUE
By setting the input parameter
" Enable synchronization", it is possible to
syn-
chronize the pulse output automatically with the block
that updates the input
variable INV. This ensures that a change in the input variable is output as quick-
ly as possible as a pulse.
FALSE
T he block has an initialization routine that is
p rocessed when the input "Restart"
is set.
T#10ms
The time between block calls must be constant. The "Sampling time" input
specifies the
t ime between block calls.
CYCLE >= 1ms
Instructions
9.4 PID basic functions
469