Target window (pos-waitstate), Function library, Positioning control – Lenze EVS9332xP User Manual
Page 92

Function library
Positioning control
3.4.9
Travel profile generator and setpoints
3−64
l
EDSVS9332P−EXT DE 2.0
3.4.9.7
Target window (POS−WAITSTATE)
Purpose
Particularly high demands on the accuracy for reaching the target position (message: Target
reached).
Function
Via the input POS−WAITSTATE the "Target reached" message can be (
pending following error has been compensated and the drive has reached the target with sufficient
accuracy (target window).
The program will not be processed until
l
the position setpoint POS−SETPOS has reached the target and
l
the input POS−WAITSTATE = LOW.
CTRL
POS−IN−TARGET
POS−WAITSTATE
POS
C1361/22
C1360/22
MONIT
POS−POUT
MONIT−P15
C1220/4
C1218/2
C1221/4
Fig. 3−24
Connect output MONIT−P15 with input POS−WAITSTATE
By the interconnection of the function blocks shown in Fig. 3−24 the continuation of the program is
delayed within a narrow target window (POS−WAITSTATE = HIGH) until the actual position value is
actually in the target window. For this the target window is preselected in a very narrow manner in
C1218/2 (second following error tolerance). In order to be able to continue the program processing
later on, the system deviation between the setpoint and the actual value, which is referred to as the
following error, must be smaller than the target window defined before. The output MONIT−P15 also
switches if monitoring P15 is switched off.
Output
Level
Description
POS−WAITST
ATE
HIGH
POS−IN−TARGET is not yet set since the current positioning is still running. The functions of the next PS are not carried
out yet.
During homing, the function is not effective.
LOW
Continuation of the program:
The program is only continued if the difference between actual value and setpoint is compensated such that the
difference is within the permissible following error tolerance.
Under code C1218/2 you can enter a following error with less tolerance.
MONIT−P15
HIGH
Display when the current following error is greater than the target window.
The output MONIT−P15 will be switched even if the second following error monitoring is switched
off.
Tip!
l
In practice, the "Target window" function only has to be used for particularly high demands
with regard to the accuracy of the target achievement. According to experience, in most
applications the standard "Target reached" message, which is derived from the setpoint of the
profile generator, is sufficient.
l
During homing the POS−WAITSTATE function is not effective. The end of a reference run is
always indicated by the homing status (POS−REF−OK).