Lenze PLC Designer PLC Designer (R2-x) - Manual (Page 670)

L-force | PLC Designer
PLC Designer Libraries
668 DMS 3.2 EN 02/2011 TD29

So besides the P-part also the current change of the controller error (D-part) and the
history of the controller error (I-part) influence the manipulated variable.
The PID controller can be easily converted to a PI-controller by setting TV=0.
Because of the additional integral part, an overflow can come about by incorrect
parameterization of the controller, if the integral of the error Δ becomes to great.
Therefore for the sake of safety a BOOLean output called OVERFLOW is present, which
in this case would have the value TRUE. This only will happen if the control system is
instable due to incorrect parameterization. At the same time, the controller will be
suspended and will only be activated again by re-initialization.
PID_FIXCYCLE
Provided by util.lib.
The PID_FIXCYCLE controller function block:
This function block functionally corresponds to the PID controller with the exception
that the cycle time is not measured autmatically by an internal function but is set by
input CYCLE (in seconds).
19.2.5 Signal Generators...
BLINK
Provided by util.lib.
The function block BLINK generates a pulsating signal. The input consists of ENABLE of
the type BOOL, as well as TIMELOW and TIMEHIGH of the type TIME. The output OUT
is of the type BOOL.
If ENABLE is set to TRUE, BLINK begins to set the output for the time period TIMEHIGH
to TRUE and afterwards to set it for the time period TIMELOW to FALSE.