Table of Contents
Advertisement
Positioning
When the actual value is within a range, the associated status bit BEE1, BEE2 or BEE3 is set to zero.
Changes in the values of these bits can trigger the following responses from the IP during
approach to a position:
Table 10-13. Switching of the IP Outputs and Triggering Interrupts during Approach to Position
Switching of the
BEE1
IP outputs
from 1 0
DAV=0
DA1 is reset
DA2 is set
DAV=1
DA1 is reset
DAV=2
Range BEE1
Interrupts
entered (BE1)
Signal from 0 1: Rising signal edge
Signal from 1 0: Falling signal edge
The following must be taken into account when defining the distance values:
•
Distance value to BEE1 distance value to BEE2 distance value to BEE3
•
Module firmware execution times.
In each firmware cycle, the IP 240 compares the actual value with the limit values for the
switching and signalling ranges. You must select a traversing speed and distance values that
enable the IP 240 to recognize the various zones (e.g. between switching point BEE1 and
switching point BEE2).
The maximum interval (t
signalling ranges is computed as follows:
t
= t
+t
LZ max.
ka1 max.
t
= Maximum processing time for channel 1
ka1 max.
t
= Maximum processing time for channel 2
ka2 max.
t
= Maximum time needed for the data interchange
kom max.
In Chapter 12 ("Response Times") you will find a list of processing times to help you compute
the suitable distance values for your application. Assuming the maximum possible processing
times for channel 1 and channel 2 and the maximum amount of time needed for the data in-
terchange, t
LZ max.
•
Tolerance of the contactor dropout times
•
Tolerance of the effect of deceleration
•
Mechanical influences (such as a change in frictional conditions)
Note
Traversing of the zones switching point BEE1 - switching point BEE2, switching
point BEE2 - signalling point BEE3 and the overtravel within the target range
should be monitored by watchdog timers.
The IP responses listed in table 10-13 are initiated only once per selected position.
10-32
BEE2
from 1 0
DA2 is reset
DA2 is reset
DA1 or DA2 is
reset
Range BEE2
entered (BE2)
) between comparisons of the actual value with the switching and
LZ
+2·t
ka2 max.
kom max.
computes to 7.5 ms.
BEE3
BEE3
from 1 0
from 0 1
Range BEE3
Range BEE3
entered (BE3)
exited (ZBV)
IP 240
BEE2
from 0 1
Range BEE2
exited (RIU)
EWA 4NEB 811 6120-02a
Advertisement
Table of Contents
